Real life performance cannot be quantified with just the number of cores. The number of cores is important, sure but do not discard the generational changes:
Each core of 13600k is faster than 12700k’s core, for example. There are multiple other improvements.
Besides that. If you manage to grab a used ($200) 12700f instead of a new ($350) 13600k, you have extra $150 to double your RAM.
Now you have a machine with a CPU that might be 5% slower but double the RAM… Or invest in a blazing fast NVMe to take advantage of Direct Storage.
It’s always about building a well-rounded machine with as few bottlenecks as possible. The 4090ti will not matter much if we keep crashing because of a measly 32GB RAM or an overheating northbridge.
If you want a better, faster CPU - 13600k is overall better. If you want a better bang-for-buck, I’d go with 12700f. They are both great mid-tier modern CPUs.
And finally:
RTX 3060
There is a 12GB version out there too, see if it fits the budget. While it may be irrelevant for gaming, running out of vRAM during development comes up somewhat often. May be a worthy investment.