Not my experience in the UK. I hate macdonalds and have eaten there three times in 30 years. But it's a cheap place to take a family to eat compared to most other options. I say this as someone whose wife is a keen cook and I know what decent food is... Definitely not defending the food but the price is often right, particularly if you have multiple kids or their friends with them.
The price hasn't gone up much in the US, but they did shift all the coupons to the app, which means you're missing out on huge deals if you don't use it. It's like 50% off once a day iirc.
But half of relevancy is branding, the other half is delivering. McD has advertising dollars still (also they own other successful franchises such as Chipotle), and in some places in the world it's not crap. It's just another over-priced food chain with some weird marketing attached.