Has native Android sideloading been disabled?

Hi.

I have a Lenovo Flex 5 with the Hatch board.

When Android was updated to 11 and ARCVM, Chrome OS allowed me to sideload Apks directly from the files app.

Basically I just had to double click the file and install it. I could even install apps from within other Android apps like you can on a Smartphone. I used this with Tachyiomi.

Now, however, I get a message saying I need developer mode to install apps outside the Play Store.

Has Google simply removed the ability to natively sideload apps in the Stable channel?