It is a trade off, and I have no idea about the state and quality of Vivado. Back in the day I was tinkering with FPGAs, the Xilinx software stack was horrible.
Ideally yes, SW should be free, but we don't live in an ideal world. This isn't Apple or Google who can give you SW for free since they take a 30% cut on everything on the Appstore besides the profit margins on the HW they sell you.
The typical customers of FPGAs are large HW companies with money to spend on SW, not tinkerers in their garage who might some day build a billion dollar company. And if you do become a billion dollar garage company, you will still buy their FPGAs because they're some of the best and the SW costs will be a rounding error plus a tax write-off. You think Anduril doesn't use Xilinx FPGAs because Palmer LUckey didn't get SW for free 15 years ago?
So there's zero incentive to give away SW, that's costly to develop, for free.
I don't think that's necessarily a hard rule, here. Nvidia won over the HPC segment by offering CUDA and PTX as a free value-add to their hardware, and ended up becoming a multi-trillion dollar company that ate AMD's datacenter market for lunch.
Giving away software to commoditize your compliment might be a good idea, for AMD.
Yeah but people would buy Nvidia chips mainly for gaming, not (just) for CUDA, so basically the massive gaming clientele would finance expensive projects that don't yet make any money like CUDA. Meanwhile nobnody buys FPGAs for playing at home en-masse. There's no equivalent consumer market like gamers for the FPGA vendors, their sales are almost exclusively B-2-B.
FPGAs isn't something most people, even the hardcore tinkerers ned at home. Consumers into hardware tinkering are more than fine with what you can do with Raspberry PIs, ESP32s, STM32 boards.
Once you learn how to get automation to work for you, it's not that bad.