One nice thing about hydraulic disc brakes is that they are strong. Also, a caliper's cylinders generally speaking move pretty evenly toward the brake rotor.
The not so nice thing is when the cylinder seals leak and ruin your ride.
I read on the internet that if you can lock up your wheels riding under optimum conditions (like dry pavement) with relative ease, your brakes are more than strong enough. Mechanical disc is more than strong enough.
"They" say it's good to check the feel of your brakes before every ride. There is a lot of varying opinions on when to get new cables. I prefer to get new brake cables before the old ones fail me in any way. Where shift cable failure is not fun, brake cable failure is extremely UN-GOOD - as in KILLED OR WORSE!
Oh, by the way, never ever try to substitute shift cable for brake cable - KILLED OR WORSE! When the cable end(s) do NOT work with your brake lever(s), go to the bike parts store and get the correct/appropriate cable(s). It's more than just the knob on the end. If you have shift cable (index or friction) size it up to brake cable - see how the brake cable is thicker.