For the record, I'm very happy with my setup, with Drupal, with Composer, with Plesk and TinyCP and... In short, I'm a happy person.

But I am not always. I am also a "grumpy old man". Meanwhile, I've developed a lament:

In short: Drupal-Commerce is really not for me. I've seriously taken the time and energy to learn how to use it, but I still find it difficult and pointless. It is too complex in structure and too rigid. When I see how easily I had set up a webshop in Ubercart under Drupal 6 and later Drupal 7, I find it utterly astonishing that something like Commerce can exist. Well, if you're selling T-shirts, Commerce might be for you, but not if you're selling books.

The bad thing is that I switched to a VPS mainly because of Commerce. I don't regret that, because it has many advantages, but still... if I had known it all in advance...
The problem is that there isn't really an alternative under Drupal. There are no payment modules available for Ubercart under Drupal 8. So I went looking outside of Drupal. But nothing really works intuitively. I even seriously tried to get WooCommerce up and running and that means WordPress. That all works, but it is not an improvement compared to the current webshop.

That is why I made the fundamental decision today to continue with Drupal 7 for the webshop. Because that will be supported until November 2021 and I hope that the desired modules for Drupal 8 have been developed before that time. Or maybe I'll choose to move straight to Drupal 9 by then.

Until then, I'm going to critically review and update the Drupal 7 site...