Or you just don't run Tahoe?
Apple is disabling downgrading across all of iOS, and starting to do the same with MacOS. So you need to keep old hardware to run older MacOS versions, and it's only a matter of a few years before Tahoe is the latest OS you can run on your Mac.
I must have taken some shrooms before I downgraded from Tahoe to Sequoia a few hours ago then.
Uhh, I guess.
AFAIK iOS has been very locked down wrt rolling back upgrades since forever and isn't super relevant to this thread. Happy to be corrected.
The M5 Pro/Max variants aren't; but an M5 Mac is a thing you could have bought for a good while now.
What you did is a downgrade in what's called the supported OS.
However, if you decide to downgrade to Catalina on an M1 Mac, it's not possible — Big Sur is the earliest version that runs on Apple Silicon.
Anyway, you cannot downgrade to a macOS version older than what your Mac originally came with. So if you buy a Mac now, Tahoe will be the minimum option.
I mean, KDE does 3x the stuff for 1/3 the cost. That's more memory and CPU for your IDE or, more likely, chrome tabs.