I do think that your age is a big factor here. When you’re young you can sit on anything and it doesn’t worry you that much, but as you get older the design and quality of the seats gets much more important.
Possibly yes but I'm only 53 !

For work, I am office based and work 12 hour shifts so I'm used to being sat on my arse for a long time.
My office chair has actual ridges in the base material design, but even this doesn't bother me at all.
The base is also rock solid with very little padding.
I can sit comfy all day long with no issues.
I have driven to work tonight with the seat protector we use under our grandsons car seat and had it on my drivers seat.
the base is 4 gel type pads with small gaps between each pad to support his car seat.
I couldn't feel anything tonight from the seat base once this was used.
Which yes I could use it going forward, but should I really have to on a £27k car !
It kind of confirms that my seat probably does have a fault on the base.
I am toying with taking a demo car out again after mine has gone back to see how that seat feels.
If its the same then Maybe it is me.
If its comfy which most people in this thread claim theirs are.
Then it probably was a faulty seat and I could maybe look at finding another MG4 to replace mine with.
There were others issues with mine hence the rejection.
Some will be fixed like the oil leak and probable soft ware updates.
But with the bad seat and dodgy fitting door trims etc, it has had to go as I have no faith in the car now.
will see this week what's best to do.
I do like the MG4 it drives brilliant, if the issues are resolved I do think I'd get another as there's nothing else out there for the money, especially brand new.