I had a LOT (100+) apps installed on an LG Stylo 3+. Never had any problems as far as storage space (no error messages about space running out, low memory, anything like that.) Recently I upgraded to an LG Stylo 5. In the course of setting that one up, I installed EXACTLY the same apps, EXACTLY the same # of apps, as I had had on the 3+. The next thing I know, the 5 is refusing to download email and popping up messages about "not enough storage space". Both phones are supposed to have the same amount of internal storage space, so why is what worked on the 3+ too much for the 5?
As Izzy has already surmised, via comment, the new device likely comes with a lot more space taken by the pre-installed apps and system data. That is what I believe is the problem. If you want to save space by stopping the default apps from updating, you can try to disable them in the apps portion of your android configuration menu, or, if that doesn't work, then this guide explains how to force disable apps using adb from a computer, though to get rid of the pre-installed versions' files, you need root. https://www.xda-developers.com/disable-system-app-bloatware-android/