Are you using the FP4? Did you activate the option to shoot photos in 48MP? A 12MP photo shouldn’t be more than 4MB.
Same for video, do you film in 4K? If yes, reduce to 1080p.
The quality shouldn’t be visibly reduced, it may even be improved.
Do you really want to sacrifice image quality for the possibility to use Google Photo storage? The situations you take pictures or videos of don’t come back. So I would for sure make a local backup copy instead of cutting the quality.
whereas storing images on Google is in itself a thing worth considering
But I don’t want to talk you into it. You have to know if you want to scan all images from google.
in google photos I’m 15GB only. in my SD 128GB, but my problem is if I lose my phone I lose my SD also. and in the other side I don’t want to pay to google. I have saved there all my photos since 2015, and in 2 months with FairPhone I arrived at 15GB…
So If I read correctly you have a 128GB SD card in the phone. Is it formatted as portable i.e. can you remove it and read it. If so buy another SD card and copy to that so you have a spare