Hey I wanted to share my workaround for this issue which basically boils down to installing a third party app.
I chose this one
A simple, safe and easy softKeys (navigation bar)
f-droid.org
It hasn't been updated in 6 years but I trust an older open source app from F-Droid more than I trust a newer from the play store (aside from the fact that I haven't found one without ads or microtransactions)
You will have to give it permission to draw over other apps and accessibility (it will guide you there after starting the app) The latter at first wasn't possible as the accessibility settings were restricted for this app, so I had to 'Settings' > 'Apps' > 'VirtualSoftKeys' and then tap the 3button menu on the top and then on 'Enable restricted settings'.
After you grant all the permissions you can enable this navigation bar by swiping up from the bottom of the screen. In the app itself you can set whether the navbar disappears after some time or stays visible permanently (you can always manually hide it by swiping down on the bar).
While this also works if gesture navigation is enabled I would recommend to choose button navigation, as this navbar will hide the lower area of any app if gesture navigation is enabled.
A very minor caveat is, that the regular navigation bar is still slightly visible, at least on my Lenovo M11 but that is a very very small price to pay for finally having decently sized and positioned buttons back.