I don't think there is a perfect solution which works with everyone on every shop hosted on every server.
Furthermore, software has to evolve and many times this procees is painfull.
Being a developer for so many years on Linux and Apple (sorry Windows guys, no love here...) I can tell you that in my experience there is no bugfree software on this planet.
As for the Prestashop being in discussion here I strongly believe that with all its shortcommings it is the best cost/performance eCommerce platform.
We're talking about a platform oferred for free you can have a shop up and running without spending a dime.
Once you need more features then of course you have to spend some but hey, this means your business is growing and you can afford it.
Technologies change and evolve every year and even a platform like PS has to do some changes if the libraries it uses changes first otherwise it looses compatibility and poses security risks.
I understand that any shop owner will like to have a setup and forget eCommerce platform but believe me this is a unicorn, a mithical creature.
And you can move your PS shop anywhere, ask the shopify users if they can do that or how much per month do they end up paying for what they discover they need, you'll be shocked.
As a PS ambassador in my country (purely honorary, it is not paid), I kind of mentor people here (merchants and devs) and do not accept clients in my country so not to create a conflict of interests but I admit I advise people in need to use it as I am convinced it is in their best interests.
I have my share of PS clients all over the world and trust me when I say that some of them are big businesses.
In the end taking care of an online business is no different than having a brick and mortar one, you still face issues and need professionals to rely upon.
It is my belief that a shop owner has to care about the business itself and not try to be an all knowing developer or an IT guy in any form.
P.S. About the support, maybe not many are aware of but PS doesn't and can't offer free support (besides the free software they're offering), they have to make a living somehow, put food on their tables, shoes on their kids feet... These forums rely on people spending their time without any pay, trying to help others as they can when they can, community work... when someone gives you his work for free can you blame him for not commiting to help you for free for life too?