You may not be aware of that in the real aviation world, when one flyes over a sertain hight , all aircraft fly on Fligh level.
In MSFS I encourage everyone : when climbing higher than 18000-19000’ press ‘B’ on your keyboard ! Same when decending between 18000-17000’ press ‘B’ again.
If we all practice this, MSFS should almost be like in the real world !
More info : Flight level - Wikipedia