Of the more than 10,000 themes for WordPress, most are problematic. The most common problems are:
The theme has bugs that are difficult or impossible to overcome.
The theme requires an annual license payment to keep it up to date. That’s almost like holding your website ransom. If you don’t pay the fee, your theme could fall behind eventually breaking your website.
The theme is unusual or complex, requiring considerable time to figure out.
The theme is made by an author who is no longer providing updates. So, your site will be vulnerable to malware or may break down as the rest of the WordPress world moves on.
There is little information about your theme, and the author will not answer questions.
So what do you do? I like to recommend starting with a known good theme. In order to fit the bill, it has to be free, made by an author who has been on the scene for a while and will most likely stay involved for a long while into the future. And, it has to be simple yet flexible.
The ideal author is probably the WordPress team. Their themes such as Twenty Sixteen, Twenty Twenty Two and Storefront are all very well-built, frequently updated, and free. The WordPress team knows better than most what is normal and compliant, and is likely to stay within the standards.
My personal favorite theme is Storefront. It’s free, solid, and continually maintained.
Storefront is a classic (non-FSE) theme that can be made to look like anything, although many layout details have to be coded manually, if you don’t like the default Storefront look and feel.
One thing that has probably prevented thousands of people from using Storefront is the preview image shown when selecting themes:
Who could believe that something as funky looking as that, with the cartooney T-shirts, could end up being the foundation of super-professional websites?
You may get a kick out of this:
I once had a client who hired someone to look over my work on a website that was nearing completion. The website made extensive use of PHP for end users to create reports. There was no ecommerce on the site.
The ‘expert’ told my client that Storefront can only be used for online stores.