secure boot is intentionally designed to lock out open source software as much as feasible within current legislation - turn it off and tell your HW vendor to shove it up their bum
at least for debian, nvidia drivers are part of the non-free software packages that come with the OS repositories, installing them is trivial. And even the driver downloads directly from nvidia are usually straightfoward to install, I have used them in the past and the last time I had troubles with configuration fiddling is well over 5 years ago
yes, installing Linux may appear a bit fiddly, however, it’s a TON easier than installing a windows from scratch. The only reason people tend to not see that is because everyone uses an OEM windows and never installs one