We are all, largely, Apple customers/users here, just like you.
No one here works for nor represents Apple.
No one here will know this, but Apple, and you will have to just wait for Apple to announce when a subset of their mobile devices will no longer be compatible with new iPadOS versions.
Currently, your 2019, 7th gen iPad is compatible with all of iPadOS 16 until next Fall of 2023.
When Apple does end full support of a subset of their mobile devices, third party app support, from the iOS/iPadOS App Store, will continue for another 2-3 years, or so, before ALL support for these devices will end.
So, currently, you have nothing to worry about.
Your device is only 3 years old, or so.
Apple supports their mobile devices for, at least, 5-6 years.
The 2014 iPad Air 2 and early 2015 iPad MIni 4 got nearly 8 years of full support from Apple ( those devices ended full OS support at iPadOS 15.7.2 ) and just got their first security update under iPadOS 15.7.
Those iPad models still have another 2-3 years of third party app support before NO apps are no longer compatible with these iPad models.
Best of Luck to You!