How to lose an old friend gently

[SonyaLoosemore]

I want to let go of my oldest and longtime dearest friend, but gently.
She's had a hard time the last few years and I have wanted to be around to support her, but the hard time is over now, her life is running smoothly and I'm realising that I don't enjoy her company, and have not for several years. She seems to make a point of not asking how I am (except in a social way), not showing any interest in the things that matter to me, mildly putting me down if I express an opinion, and even telling me I'm wrong about about the weather patters in the area I've lived in for 20 years and she occasionally visits. I've tried several times to say I'm not happy with all this and wondering why she does it, but she says I'm imagining it and our friendship is just as it has always been. But it isn't. I used to love being with her and we talked about everything.
Since she doesn't understand what I'm going on about, I don't think there's any point in trying to mend things, and I don't want to upset her more than necessary. Will it work to contact her less and less often and say I'm too busy to meet up if she suggests it, and hope she loses interest completely? I am pretty sure that she doesn't like me any more so surely she won't mind much?

I would find it so much more difficult to break up with a friend than a boyfriend. I would probably do the slow fade where I don't text and am always busy when they ask to meet up and just hope she eventually gets bored , gets the hint and gives up.
Such an awkward situation when it's a friend. I have had friends ghost me before which was quite hurtful so wouldn't recommend that.

Yes, just be less available and let the friendship fade.

Yes just let it fade less contact. No point keeping it going if not much in common

Make sure to be upbeat during your slow fade. Don’t let her think it’s because you are stressed and struggling!

How often do you see her?

Do you think she's always been like this and you've got to a stage in your life where you won't/can't/don't tolerate it any more? I got to an age where my tolerance button for people who were a bit take and no give just got stuck in the off mode. I feel better for it but it did mean I just gradually allow some friendships to drift off into the sunset.

If she really is your oldest and dearest friend would it be worth one last really forthright conversation with her? Not a subtle mention (that she can steamroller over) but a no nonsense "This is how it is for me" with examples of how she is, what she's said, how it made you feel. If she tries to brush it off then you can either say you need to put some space between you or just let it drift.

Thanks everyone for your helpful comments.
@CurlewKate We now live 250 miles apart now, so don't meet often in the course of things, it takes a bit of planning and commitment. When we lived closer, it was at least once a month for more than 30 years, including Christmas and NYE and holidays, then two or three times a year after we moved, and more recently about once a year, always initiated by my friend. She asks to come and stay, seems delighted to see me at first, but soon it starts to feel hard work.
@WildGarden I have tried speaking plainly a couple of times and been met by indignant denial, eg 'Of course I'm still interested in you.' 'I don't know why you would think I'm being less friendly considering I invited you to my birthday lunch'. So I'm not feeling hopeful about trying again, but I will do if she realises that I'm avoiding meeting in person and asks why.
Like you I am getting less tolerant as I get older. I do think my friend's behaviour has changed in recent years, but perhaps I am also noticing it more these days and have more time to dwell on it.