I modded several PS3s back in 2019-2020 and flipped a few on eBay before they cracked down. I really enjoyed taking them apart, cleaning, putting new thermal paste on, etc. Never successfully delidded one, that was always the ultimate challenge in my mind. The last one I did was a gift for my son-in-law back in 2022 ish. I had always loaded games the standard ftp routes, etc. but the one i prepped for him, I experimented with the app linked below - on the playstation 3 itself and it was phenomenal... direct download and install directly from the PS3 itself. Including games, addons, etc.
https://github.com/bucanero/pkgi-ps3
also, NoPayStation https://nopaystation.com/
https://github.com/StreamerApp/Streamer
works great on ATV tvos. Worth the $10 for the pro version which allows real-debrid Api key use connected to streamio and other sources.... pair with infuse pro and your ATV will be set
Telegram groups are where I've seen the most. Another guy just posted multiple IPA repositories yesterday in /r sideloaded. Search for his post entitled, "Repos for Feather"
I sideload apps on my ipad pro, but as others have stated, it's nowhere near as straightforward as doing so on Android. I mainly decided to do it after my wife continued to spend $$ on "coins" and "gold bars" for Candy Crush on her ipad. It was cheaper for me to buy a developer account and sideload modded versions that have unlimited coins, etc. She's stuck in the apple ecosystem, even though I did try giving her and Android tablet to try out.
If you decide to try sideloading on IOS devices, and you spend the $99 for a developer account, I recommend using Sideloadly or something like Altstore to sideload apps to your device vs. a service that requires you to provide your certificates from your developer account to attach it to their ecosystem. Maybe some are legit and won't compromise your developer account credentials, but I prefer standalone tools that I self host, for security reasons. They are more work thought.
A compromise might be to use a services like Singulous that sells you a "slot" on a developer account for $10-20. The problem with those is they periodically get revoked and your sideloaded apps must be reloaded. For more info, you might look at reddit /r sideloaded.
Best of luck!
I never understood the karma thing... guess I'm old school - post to help others where you can and let that be the "karma" you are known for.