Having been on the alpha for both for ages I would say NO. The direction WTFZF and SS are going in are diversifying even further too, and as others have mentioned the only real similarity is top down spaceships with you flying. Yes you reconfigure ships in both but the customisation is incomparable. And fleets are not something in or planned in WTFZF (It was explicitly said by a dev a while back). Interactions with NPCs are currently evolving in WTFZF but an interactable marketplace for the player would not fit the game, maybe the ability to purchase or quest for crew/specific 'legendary' blueprints is a possibility but nothing like what SS has.
I would suggest getting WTFZF and playing it before judging.
Because I ageree with this.
I'd say there is more similarities between Call of duy and Battlefield then there is with Starsector and W.T.F.. From what I see from Youtube videos they only play the same as they are both space games and play topdown.
Thats's about it.