A strong recreational cyclist might have an FTP of 4 w/kg (FTP = functional threshold power = power one can maintain for an hour in perfect conditions). I can hit that target at peak fitness, but most of the year, I'm well below.
Mathieu van der Poel is about 75kg with an FTP above 400 watts. Over 5w/kg. He's a relatively heavy professional cyclist, but an amazing all around cyclist who can climb, sprint, and win just about any day.
Tadej Pogacar, the current Tour leader, weighs about the same as me (68kg), but has an FTP somewhere around 400 watts. Or 5.8w/kg.
Of course, 1 hour power isn't everything. The 5, 10, and 20 minute power these guys can generate is even more mind-boggling (not to mention more critical on race day, as they have to cover attacks and break-aways).
Drafting (riding behind another cyclist) can cut the effort by about 30%. So, the rider at the front of the peloton might be doing ~400 watts (and likely more, especially in the last hour of a ~5 hour stage), while cyclists in the back are only doing ~280 watts.
To put that in context, as an average masters cyclist, 400 watts is an output I can do for a couple of minutes at most. And 280 watts is an output I can maintain for about an hour.
A top Tour overall contender will average >200 watts over the stage, and on a critical climb, might average 350-400 watts mostly solo (or in small groups) for 10-30 minutes.
Discussion of Uran's power in a stage win from 2017... https://www.cyclingweekly.com/news/racing/tour-de-france/rig...
Not from the Tour, but analysis of a young pro's power during his 2019 win at the 1-day Amstel Gold race... https://cyclingtips.com/2019/04/mathieu-van-der-poel-power-w...