Better use php7.3 or install php7.4?


After a default installation, I see that the version of php is 7.3. I would just like to know :
— why this choice, and not propose the 7.4 on Ubuntu 20.04 ? There must be a good reason
— I saw that in edit/server/ you can check the box to install php7.4. Is it risky? Could I lose functionality?

Thank you for your expertise and have a good evening!

While most applications don’t have a problem with PHP 7.4 there are a few. For example, nextcloud only recently made their app compatible (maybe 4 months ago?) and while Wordpress runs fine, then there are a lot of plugins which haven’t been fixed to run on 7.4.
So for me, 7.3 is the “safe” choice. And its easy enough to increase the default value of PHP in the Package, or to turn on 7.4 for each User, or for each Website individually.