Realistically, if you couldn't create that catalog manually without powerstore, then probably not... the product specification and option selection process is very specific and multistage on the example site. It would be difficult to get Powerstore to mimic that without a lot of customization.
I mean, if I were hired to build it I'd probably still use Powerstore as a starting point, but I could create that catalog experience manually with the help of Data Bridge.
It is unrealistic to think there wouldn't be a ton of hand coding on the product catalog and options specification process getting the item added to the cart. The checkout, orders, user management, CMS, etc from Powerstore would all still be applicable so it would still be relevant which is why it could still be a time saver to use over doing the entire site manually.