There is plenty of ventilation. One in, two out(because PSU fan).
Node doesn't equate to TDP. The 13900k is on a 7nm node and pulls over 300w, the 4090 has a 450w tdp on 5nm.
Node size impacts energy consumption and efficiency.
And smaller components would mean less of a "surface" to create resistance.
I know what was required to adequately cool an FX vs. a modern Ryzen with the same core count and in the case of the Ryzen somewhat higher clock speeds.
But I will agree that if the architecture changes, like with video cards cramming more cores and increasing frequency you will get a higher TDP.
GPUs are probably the only segment that has continued to evolve at a high rete in recent years, since CPU speed and core count have stayed mostly the same for most product lines.
Hell, if pure speed is what you want I think that the old Centurion/FX-9k cclocks higher at iirc 5Ghz or above.
But that abomination required extreme cooling IIRC and they had to "cherrypick" the highest quality silicon for those units.