[schroeding]

IMO "not ideal" is still a euphemism. Even if you do this, often throwing away decades of branding, there is a high chance that Lieferando aka Just Eat Takeaway.com will still not only register a similar domain again, but that it will rank higher than your website anyway, even with the "worse" domain.

You have a small restaurant, often using things like WiX or Squarespace, against a tech company with a dedicated SEO team. Good luck.