Is $10,000 to remove popcorn ceilings from the whole house a fair price?

I am a first-time home buyer. I was quoted nearly $10,000 to remove the popcorn ceilings in my whole house with no furniture in the home. I started to remove it myself. I did my bathroom just fine; it came off super easy, and after hiring someone to renovate my bathroom, they skim coated it with no problems, and it looks great. I started a small space in my dining area, and this one is giving me trouble because I think it was painted over. Where the ceiling meets the wall, the texture is stuck, and I’m having a hard time removing it. I tried putting silicone in the corners to smooth it out and then paint over it, but it still looks bad. I thought maybe I just need to skim coat but read that joint compound will not stick to silicone. I feel stuck and am looking for advice on what to do next. I heard tools don’t work well with painted-over popcorn, and I still have to manually scrape the edges, which is where my problem is. Adding drywall is my last resort if I can’t fix it. I wet it, tried to scrape it, sand it, wet it again, and scrape. The problem with the corners was the drywall tape was starting to come up the more I was trying to get it off. I figured I shouldn’t remove the tape. I removed the popcorn everywhere else; it’s just the cracks (where the ceiling meets the wall) that look bad. I'm wondering if I can do this even if there is already silicone in the inside angle, and if I need to skim coat the entire wall below it if that part has already been painted.