I can offer suggestions that may be better although not a perfect solution
Get a Roku device that works with IR (simple) remote. Express, Streambar are examples, not any of the sticks.
3rd party universal remotes have Roku codes and maybe you will find one that has a better button layout. Or a "learning" remote.
You can also try upgrading to voice remote, or smart speaker, to get voice control of Roku.
Or install Roku app on a large format android phone or android tablet.
Final option is to find someone who can make a bigger box with bigger buttons, which can mechanically press the buttons on standard Roku remote stored inside.
Sadly what you report is a common product with modern electronics. Also the craziness of touch screen radios etc in cars.
