Whenever I have flown with my larger power bank the security staff at the airport have checked the printed rating on the power bank.
I don't think they check laptops, etc. but those limits are probably set by other consumer laws (i.e. you can't sell a laptop with >100Wh if you want people to be able to fly with it, which is pretty important for a laptop.)
And yes, the consequence of any battery fire is quite high but the likelihood is very low so I think it's fine. Note that you're not allowed to charge li-ion batteries during takeoff and landing stages on a flight, which is one way to reduce the risk as cabin crew would be seated during that time and it would be a lot harder to tackle any fire.
The biggest risk is things like vapes which use 18650s. These batteries are not really safe for general consumer use, as the plastic wrapping that isolates the positive and negative can be easily damaged (the shell on most 18650s is connected to negative IIRC.) So it only takes a bit of metal in the wrong place to cause a short and those can be extremely dangerous. I don't know if they are restricted or not.