my argument is that relativity changes aging, but not time.
You started from reading about, hard to grasp for layman, twin's aging thought experiment, and immediately you were put off.
You should start from much easier to grasp decay of unstable particles,
where are used Special Relativity equations to predict something which you can actually see on your own eyes in particle detector (which you can build literally today for couple dozen usd)..
I wrote example equations here:
Using them you can predict decay energy, velocity, kinetic energy, momentum of newly created particles.
Then compare with what you have in particle detector.
A famous person once said "If the first time you hear of quantum physics, the concept does not immediately shock you, then you are not understanding it correctly."
In quote it was "quantum mechanics", not "quantum physics".
Special relativity is widely used in particle detectors like CERN/LHC, in computer software, to recreate impact of particles with other particles, and production of mesons, baryons, and leptons 2nd and 3rd generation, high energy gammas, etc. etc