@GravitySpoiled Sorry to hear you’re having problems. I also have a Pixel 6, have used OsmAnd for ~a decade and haven’t seen anything too severe. The only maps I keep on hand are the World maps and the US state of California, including contour, hillshade supplements and the wiki. OsmAnd says it’s 4.1 GB worth of data. I do have lots of free space on the phone though.
I did bulk up on this same phone when on a long bike tour a while back, adding the files for British Columbia, and the States of WA and OR in addition to CA, and their contours and wikis and performance was OK. I used it at freeway speed yesterday and it seemed to function fine. Wonder what’s going on w/ your phone?
@GravitySpoiled OSMand began on Android, hence the name, and only became available on iOS much later. I recall the original iOS releases received lower reviews until quite a bit of patching was done. Strange it’s running poorly for you. Their support and forums are pretty active - have you taken this up there? Best of luck.