The security and privacy features benefit the majority, of which you clearly are not, so there is an escape hatch for you; turn off SIP. Just don't disable it for typical users.
Restart macOS, holding ⌘+R. Open Terminal. Type `csrutil disable`. Restart macOS again.
Any day now…
But as far as I'm aware the reasoning is that if there's a way to access something from a normal user account (with admin privileges) it can be abused somehow.
Maybe a "key" would be the ability to boot/log in to a special mode with SIP enabled. Disabling/enabling it approximates this, but as far as I know an update will generally destroy your changes because Apple will just overwrite everything.
Stallman was right about "treacherous computing".
https://forums.macrumors.com/threads/if-you-disable-sip-all-...