Your heatsink is mounted backwards. The fan should push the air through the heatsink, so the PSU/back case fans pump the heat out.
You're running a beefy RTX card + 5900X combo... in a 2005 case?
C'mon, also get a decent case that provides better airflow. There're plenty of NOX cases for $50, with 5-6 fans.
You can get a cheap liquid cooler for $50 or so, they do work pretty nice as the heat is pumped out of the case much better.
Still, modern cpus spike a lot, the dies have gotten smaller so the power can't be evacuated so effectively as older (larger) cpus.
In any case, 72ºC is perfectly fine, newer Ryzens are even worse, they boost all the way up until reaching 95ºC and only then they start slowing down!
90% of computers running stock coolers work at this temperature under load or even higher, it's not a concern at all.
Rising the power of that Ryzen might get you into 5GHz, with much increased power and temperatures, the gain will be marginal.
My i7-3770K ran at 85-90ºC for 10 years, no problem, this was due Intel using crappy thermal paste used instead soldering the die to the IHS like in previous generations.
Any modern CPU can run naked, they will throttle down as required to avoid getting too hot, this is not like in 2000s AMD Athlons where they burned down miserably.