I was more concerned about the TPM requirement purely due to not having one in my desktop that's otherwise perfectly capable of running Win11 Pro (I know because I've been running Win11 for months on it via the Insiders Program). Yes, the desktop is 8 or 9 years old now, but it's still a 6 core I7 with 64GB Ram and a suitably fast SSD (not nvme, though). To me, it reeks of planned obsolescence in the name of pushing Windows Hello, that I don't need.
I did look into what an upgrade to add a TPM would cost. I was looking at over $400 for a like motherboard to support TPM (without an actual TPM chip), but I'd also lose SATA channels I currently use. At the point of having to replace a motherboard, it starts looking attractive to do a full rebuild, but that's difficult with supply shortages and inflated costs currently.