This one brings back a lot of emotion. My mom passed this past January, and she had been in a care facility for a little over 2 years prior to her passing. A few things that I've learned since 2021 on this.
1) You really need a power of attorney AND a medical power of attorney. Luckily, I had these when my mom's memory started going, but I've talked to several folks that I work with about getting this done with their parents and their parents get fighting mad when it's brought up and won't even consider it. Use every resource that you can to get this done (doctor, pastor, etc...), because as others have said, they tend to listen to others over their own kids.
2) Bank accounts - you or a sibling (or both) need to get your names put on your parent's bank accounts. That will allow you to use their accounts to continue to pay for stuff if they are mentally incapable of doing so.
3) If you can get a Lady Bird deed on their house, do it. That will prevent the house from being utilized to pay any medical bills. But, there are also restrictions on this that you'd need to talk to a lawyer about because I can't remember all of them at this time.
4) Scammers - They are out there in droves and prey on older people. At one time, my mom had a 10k check and a 5k check written out AND in an addressed envelope for "fees" because she won the publishers clearing house sweepstakes. With her slowly increasing dementia (meant in a good way here), she never could remember to buy stamps. At the same time, she received a personal check for 500k in the mail from a dude in Virginia and tried to deposit it. I was on the bank's board at one time, and they knew me well, so they called me after she came through the line, and I went and got the check. I actually called the guy who sent the check to her, who was older, and he absolutely went off on me saying "that check is as good as the gold in Fort Knox" among other things. I finally got him to shut up and told him that he was being scammed, but he really wanted nothing to do with it. I did call the local police, but they said there was nothing they could do since no money changed hands, which I totally understand.
5) Will - they need one, and with that will come the POA and medical POA.
6) Patience - I'm normally a very patient person, but I absolutely lost it with my mom on multiple occasions about not paying bills, etc... This is where your name on the bank accounts comes in handy.
7) Driving - my mom had a hard wired route that she drove almost every day. The biggest thing is she'd call me and say her car wouldn't start and I'd have to find where she was and get her fixed up. 99% of the time she hadn't put the car in park. Now, she was a good driver when she knew where she was going. I rode with her many times with no issues. Her stroke put an end to all driving. I actually installed a HUM (from Verizon) on her vehicle, which allowed me to follow her when she was out. It was a very good purchase for that time in her life.
8) Tech issues - repeating what nyc has said about this prior: I had to go to her house many times to "fix" the TV remote. It drove me crazy. Also, calls at all hours of the night ("I was just going through my phone and saw I'd missed a call from you": that call was 9 hours ago....). Be ready for it because it will happen. Luckily, we were 5 minutes away...
9) I was almost to the point of having to put my mom in a care facility, but she had a stroke right at 3 years ago that took out her right side. That actually made my decision for me with regard to getting her into a facility.
(10) This process can be very overwhelming. If you have siblings, you better put aside your differences if you're in a strained relationship because this will strain it more. Trust me when I say that you'll need to lean on each other. I had to go through this process by myself as my sister had passed away a year before my mom had her stroke, and it was very taxing. It would have been nice to have had her there.
So there is what I have to offer on this. Thinking about you as this is a tough road to hoe, and you won't get it all fixed in one day. But, do a little at a time....