The main problem I've had with 3rd party "essential" blocks and addons, (such as those required to add responsive design breakpoints for layouts) is that I'm never confident the supplier will be around in 12 months and the site owner will require me to refactor the site.

It's actually one of the reasons I've used page builder like Elementor, despite the speed issues, I'd rather a slightly slower site which provides the functionality required and remains functional in 3 years instead of a faster site which is no longer functional because the original block author abandoned the platform.