Feynman's Light Clock

Feynman thought that time ran faster in higher gravity because his light
clock in a rocket ship ran faster the faster it accelerated. The light
flashes bounced from end to end.
Source: The Feynman Lectures on Physics Vol. II Ch. 42: Curved Space
https://www.feynmanlectures.caltech.edu/II_42.html
SEE FIGURE Fig. 42–17.A clock at the head of an accelerating rocket ship
appears to run faster than a clock at the tail.
He said that time would also run faster because all processes, such as
your heartbeat, would run faster.
Of course, now relativists say the opposite about GPS clocks:
Less gravity = faster clocks.
Then is it warranted to conclude from the rate of clocks that time
itself (all processes) changes?
No. Clearly, it is not.
Relativists now will say that atomic clocks are better than light
clocks, so we can judge by them.
The clock's rate is only one process, so it cannot be equated to the
rate of time.
This proves that if you have at least an 85 IQ and actually use it, you
are more intelligent than Einstein and his followers.