I have really bad pain in my heels in the morning. As the day goes on, it lessens. Orthopedist says that's because I loosen up over time as I flex my heel over and over. Then at night, it tightens up again. Walking on a hard surface aggravates it, as does vigorous foot activity like running or strenuous hiking. Age is a factor, and so is a predisposition to arthritis. Your heels lose natural padding as you age, and your tendons lose their natural stretchiness.
There are a few ways to approach plantar fasciitis. One is to do stretching of the plantar fascia in the morning. Pull (or press) your toes up towards your belly, keep them there for a ten count, and release them. Repeat several times on both feet. Use a stretchy band or lean forward with your foot flat.
There is a boot that can be prescribed that will keep your feet at a right angle to your calf while you sleep. That prevents your plantar fascia. from tightening up overnight.
You can buy shoes that offer extra cushioning to your heel. That way walking does not aggravate your already inflamed fascia. I buy most of my shoes through a company called Orthofeet. My wife buys shoes from the Hoka One brand for a similar reason.
It also helps to soften your floors in any way you can. Thick carpets, extra padding. Foam mat floor tiles in work areas. Especially if you barefoot a lot.
According to my orthopedist, surgery and cortisone injections can cause more problems than they fix. Should be avoided unless you are crippled.