A few of the community have requested the gx290 be supported by /e/ because it is a rugged phone, and the gs290 is already a central part of /e/.
https://community.e.foundation/t/gigaset-gx290-plus/34260
https://community.e.foundation/t/gigagset-gx290-rugged-phoned/27763/21
Dont know just how rugged the gx290 is but I have the gs290 and it is a very good phone for the price.