I am thinking of ordering the MSI Pro B650M-P. I just noticed that there is no rear USB-C Port. I am wondering whether I should spend more for a board that has that port. How important is that port?
USB-A (old fashioned rectangular) is limited to v3.1, which has a max speed of 10Gbps.
To go faster than 10Mbps you need USB 3.2 gen 2x2, which is 20Gbps. This can only be done with USB-C.
And having a USB-C port doesn't necessarily mean it can do 20Gbps. You need to read the fine print in the product specifications. (Same for USB-A, with most average USB3 ports only going up to 5Gbps.)