If teams had their own tier list Samus probably wouldn't even move. She still lives forever, but now her recovery gets buffed because it gets harder to edgeguard her. On the flip side, her recovery still takes a long *** time, so if your opponents happen to repeatedly hit you off at high percents, it's going to be a 2v1 for your partner.
In teams unsafe things become a little bit safer, eg, grab, charge beam, etc. But overall they can still be dangerous to your teammate.
Another tradeoff is missiles, they're only useful if you're careful with them or your teammate knows how to avoid them. Overall they're much more situational in doubles.
tldr; samus is okay in teams I guess
You really should be doing this in singles with missile cancelling already.
Missile, bait a shield/predict a jump, punish, punish, punish