ah, debloating and optimizing phones is a never-ending loop because android constantly gets updated and new junky apps appear. it also depends on the manufacturer and the brand of the phone you buy. in my case it is a cheap xiaomi I grabbed while it was still fresh. chinese phones and software is a nightmare in terms of privacy and bloatware.

the best thing you can do to debloat and claim your privacy again is to install another ROM (system) on your phone, like grapheneOS or other privacy oriented systems. the problem is that most of these only support google pixel phones.

so, here's a detailed list of what/how I optimize mobile devices:

(in the end of this I'll give you some good apps).

1. google software: google's services are hardly integrated in almost every android device, which is not good except if you 100% trust them (I don't lol). google's apps don't trust your privacy and they run in the background and drain battery. to get rid of google and make yourself independent from their nonsense, I advise the following: -disable EVERY "personalized", "anonymous" data collection options "tHaT imPrOvE THeiR pRoDucTs". find these as much as you can because this should significantly improve your privacy. they're usually located in the privacy section of your android's settings and google account management page. -find alternative apps. there are plenty of youtube, mail and browser apps that can fully replace and even improve your overall experience that doesn't directly give google your data.
2. system apps: apps like mi player and xiaomi browser are useless except if you want to freely give the manufacturer all your searches/data. -disable and uninstall apps: do this to as much apps you are allowed to do. you can disable google play services (but I don't recommend it since MANY apps depend on having google services propely set up) and some others. -stubborn apps: for stubborn apps that aren't allowed to be uninstalled, there are a few effective workarounds. for advanced command line users I recommend connecting the device to your pc and use the android debug bridge. for less knowledgeable/confident users, I recommend the inure app manager which can be found on F-droid.

what is inure app manager?

it is an app that can be used to effectively debloat your phone and give you some other useful features. it uses wireless debugging to act as a more user-friendly android debug bridge that has a user interface. to connect inure app manager through wireless debugging, there are 2 things you require: shizuku app (F-droid) and developer options (I assume you know how to enable that). shizuku is an app that enables other apps to connect to wireless debugging. after that you connect inure to shizuku and you're ready to go. I advise you to be careful of what you uninstall because some apps will render your phone unstable/unusable upon their deletion.

3. custom, everything: from browser to default phone app (note that some brands of phones do not have options for custom default phone apps, galleries etc). forget stock launchers and software, FOSS is the way to go. I'll list it in the end as mentioned before.

so, to conclude, the main thing is to get rid of google and stock software. I'll list apps I use and some good alts to stock software:

-launcher: nova launcher (lawnchair, ion and fast draw are among my favorites) -dial: fossify phone -messaging: fossify messages -browser: firefox (fulguris is another good option) -gallery: fossify gallery (aves gallery is great too) -audio: vanilla music player (vlc, soul searching, apollo, etc) -video: vlc -email: thunderbird -voice recorder: fossify voice recorder -software store: aurora store and F-droid with izzyondroid repo and a few others -ebook: librerafd (F-droid) -calendar; persian calendar -calculator (yes I don't trust xiaomi calc): calculator from F-droid

and many many others. for most maxed privacy as far as I know you can get, buy a google pixel and install a custom ROM + proton mail instead of gmail + vpn.

all of these effectively improve performance and battery and greatly ehnance privacy.

hope this helps?