Things that you can try to make your Toyota Tacoma seats more comfortable include:
Changing the seat covers – This will freshen up the perceived comfort of the cushions and the breathability of the seat fabric. There are plenty of option available that have more or less cushioning, depending on your needs. On top of this they will also protect your original seats, so this is a win-win.
Adjusting the seat positioning and height - If your front seats are adjustable then try to move them towards or further away from the front or recline them. Also you may be able to adjust the height which can help those with still joints.
Adjusting the lumbar support - sometime simply adjusting the lumbar support can be a game changer for back issues. Play around with this until you find the sweet spot.
Replace the seats - If you have access to a scrap yard, there’s a good chance of finding discarded seats that are still in excellent condition and may have additional features when compared to your original seats.
The only thing to keep in mind is that this will require a component eve of DIY skills to do yourself. Paying a professional to do this for you will, of course, cost extra.