That The Moon is tidally locked to Earth? It's a one way relationship - The Moon is tidally locked to Earth, but Earth isn't tidally locked to The Moon.
I assume you'd have trouble extracting as much energy from any tides that might exist on The Moon, if it had liquid oceans.
"Its rotational energy was spent"
"Tidal forces cause a lot of stress on celestial bodies",
but not with the Earth-Moon system because the Moon's
"rotational energy was spent".
I'm not disputing that the Moon is tidally locked, just the consequences in terms of tidal forces. But perhaps the issue (and maybe err) is in confusing rotational energy with orbital energy and the relationship to tidal forces.
> "Tidal forces cause a lot of stress on celestial bodies",
Correct
> but not with the Earth-Moon system because the Moon's "rotational energy was spent".
Not now. But the Moon is still stretched tidally (and permanently in that position)
It causes a lot of stress when the tidal pull happens while the body rotates (w.r.t their main "puller" - the Moon rotates, but not relative to the Earth)
And this pulling/stretching is what caused the Moon to stop rotating
Maybe Wikipedia explains it better https://en.wikipedia.org/wiki/Tidal_locking
Taken as a whole, I read the comment as possibly along the lines of "This seems reasonable (or obvious) - you end up with dead lifeless geologically inert celestial bodies like the moon if you take away the stress of tidal forces / (varying) gravitational pull", as an example to contrast/compare against.
The Moon is tidally locked to Earth. Its rotational energy was spent by rotating it while being tidally pulled.
A good analogy is: get a rubber ball, squeeze it on a flat surface and roll it (while squeezing it). That's what happened to the Moon.