Monterey will work fine on you 2017 MacBook Pro. I have no idea why people try to scare others into not upgrading. One anecdotal experience on a single piece of hardware is not representative of the entire population.
Monterey will be dramatically different from Sierra, though. Especially the loss of use of any 32-bit apps you need. You may have to upgrade those, if even possible, or find a replacement. You cannot run 32-bit apps on Monterey.
Go64 can help identify your 32-bit apps. You can also identify them in System Information, Software > Applications.
I think the installers will now show a list of recently used 32-bit apps before it starts the installation.
If you have a spare external SSD, you could install onto that and see how it works. You could even Migrate your user data to that install. If it all works, you can then work on the internal drive.
It's actually somewhat difficult to do what you want. You would need to create a Bootable USB Installer, boot from that, Erase the drive, then install the OS. When the Setup Assistant runs you would Migrate your user from the old to the new (either direct connect or from Time Machine backup).
However, when you download the installer for a newer OS than you have installed, the downloaded installer will not be a "full" installer, and you cannot make a bootable USB installer from that "stub" installer.
You would need to update your Time Machine backup, then Upgrade your Sierra install. Once upgraded, you can download the full installer, create the bootable USB, and Erase/install Monterey "clean." Migrate your user from the Time Machine backup.