Hi,
Before any major version update is released, we release a Beta version for early adopters and for theme and plugin authors to help them make the needed compatibility changes before the official release.
You can see an example here: https://github.com/pojome/elementor/issues/3706
During the beta period, we fix and improve the code based on the feedback we receive from users, making it more stable for scale. Once we feel safe enough we release the stable version.
We cannot always know exactly what causes every bug right away. We currently have more than 600K active installations, which means we have 600K different configurations (plugins, themes and servers). Therefore, immediately after the release of the version we check and examine every issue that comes and we fix it immediately.
We prefer to address issues immediately after they happen and release the patches immediately, even if it might seem strange to users that we’re releasing a lot of patch versions in a short time.
We try to learn and improve from version to version so we can be better, because we understand the magnitude of the responsibility we have, but if you want to help us, I invite you to subscribe to our mailing list for beta users so you can experiment with new versions in the development area: https://my.elementor.com/beta/
I hope I answered your questions,
Best regards