Best Website Builder has to include lots of reasons for choosing the best one. There are pretty much 2 different types of websites. We kinda need to discuss that first.
The "traditional" looking website has been around since the Internet started. The other style of website building system came along called "Word Press" that has grown significantly since then. Once you accept that, we can then discuss the types of builders and who does it best? Another aspect to strongly consider is how technical you are and or want to be? The "Word Press" type of site building requires a fair amount of technical knowledge, plus the desire/ability to keep up and constantly be updating your website.
We also need to acknowledge that a website is just an expansion of the domain (name) that has been chosen. The domain is kinda the book title and the website is comprised of the Chapter Titles and all the content and pictures within the website. Most(?) website builders don't "host" the domain name. You have to research what domain name you want/need and then go to a "Hosting" company and purchase the domain name URL. Once you have your domain name, then you need to research what website building system you want to use. As you research all the different types of building systems and companies, notice that very few actually guide you as to how to structure your website. They'll provide all types of tools, but no real guidance as to organizing your thoughts and the actual process of what Google wants in a website.
The Word Press System allows pretty much an unlimited source of methods and Apps to build out your website. Therefore, it can be quite fancy with lots of bells and whistles. That's all well and good, but not at the expense of focusing only on the Look and Feel of the website?
The Traditional types of website building companies are kinda the same - they'll provide lots of neat tools to build the site - BUT - no real guidance as to how to structure your content, keywords, pictures, titles, etc.
As I stated several times throughout this website, looking pretty is really only 49% of the equation!! The majority - 51% - has to be on the structure of how to build and design your site so Google finds it and actually likes the way you structured it!! It's kinda like a "Test". Google looks for some very specific procedures and methods of content structuring, picture identifications and of course SEO.
Don't matter none if your website isn't displayed on the first page or two of search results for whatever your primary keyword/URL is!!
If you have already built websites and actually understand and know what Google wants, then have at it with whatever best website builder you've been using. When I first got into this, I searched for several years trying to find an all in one system - training, researching, hosting, support, teaching, etc. etc. I didn't want to have to learn coding and I didn't want to be too technical either - focus on the website itself - not the techy side of it! I literally spent thousands of dollars to no avail. I stumbled thru building several websites that "looked" OK, but I'll be dammed if you could find them by "Keyword"!! You had to type the domain name to find them!!!!
As I've said, the tools and designs are all available thru just about any website builder. If you like to be the techy and in control of everything - all the time - then Word Press is the way to go.
I still have to come back to the teaching and structuring of a website. Google absolutely requires certain things on each page to be accepted by them and therefore indexed within the first few pages of search results.
The Best Website Builder has to provide accurate, consistent, training, teaching and support. If you've ever used Word or Publisher, you'll figure out how to build a website page on anyone's site. However,I have found only 1 company that actually does all of that - at a very fair price!!
Solo Build It! or SBI for short.
They actually try to teach you what you need to know BEFORE you even purchase your domain name. They have a 10 Day, self-paced teaching system that is superior to anything I've ever seen. It's in Video, Audio and Text format. Their entire Mission is to provide the best possible teaching and training for you so you are successful. They have the true entrepreneurial spirit!! It is an all encompassing system - Help you figure out what your best topic (URL) should be, what keyword phrases should be used with the URL, how to structure your page building so it is found and liked by Google, how to design the Look and Feel of the Website and all the necessary tools to accomplish that. They indirectly Host the url for you and provide all the tools needed for Responsive Design, widgets for best HTTPS encryption, GDPR requirements, Analyze your page before you build it, etc. etc. All of this with incredible Support!!!
They have the typical website building system as well as a Word Press Plug in for the best of both worlds. Solo Build It! has all of the tools needed to build a successful website and keep it growing. Their prices are very reasonable - the teaching is worth it - believe me!! I spent a ton of $$ and got no where before I found SBI.
I've been using them as my best website builder for over 10 years now!! I still believe they are the best website builder - because they prove it to me week in and week out - every year!!