Link is pretty mediocre, maybe outright bad. I put him at mid-low, or maybe even low [as I haven't labbed out some of the characters I've heard are worse than him very hard]. He's got a lot of flaws that become more and more apparent as the level of play rises, and while his grab is one, it's not a back-breaker on its own, just one more straw.
I think link is top 10 in pm. Of course tier lists don't say much in pm as the game is very balanced, but he has amazing combo game, neutral, recovery, and kill confirms which makes him a very good character imo.
Combo game? No not really. On fastfallers it's decent, but that's true vs most. If you DI his combos well, his best thing is really just trying to not let you land with uair.
Neutral? ...again, not really. You can deploy hitboxes to go through boomerangs and bomb pulls take a long time [long enough for many characters to punish almost on reaction, if not outright on reaction]. His nair is worse than in Melee and jab is quite slow, while his movement speed is only envied by maybe Jigglypuff, lacking any semblance of a threatening dash-dance and being poorly suited to aggression.
If you don't know how to navigate projectiles, then sure, it's good, but if you understand how to weave through his stuff, he's got bad close-quarters frame data and has to rely a lot on CCing, which most of the good characters break VERY quickly.
Recovery? It's... passable? It's really on the wrong side of good, where tightly timed ledge refreshes will spell his doom very quickly. It doesn't go very far on its own, and you can interrupt bomb jumps with a variety of tatctics [including just jumping into up+b or throwing projectiles at Link or the bomb]. It's not as bad as some make it out, but it's very much edgeguard-able, most people just don't put in the time learning to do because Link has never been very relevant.
Kill confirms? Eh... his grab is risky, spin attack can be punished with Falcon Punch out of shield [I'm not exaggerating, test it if you don't believe me], dair has a lot of lag and isn't safe when it bounces on someone's shield either, fair is passable but very predictable and easily DI'd, and he doesn't have ways to reliably set up into these things unless someone DIs badly [not reliable against good players] or gets grabbed [which is risky and also doesn't fully function correctly].
He has tools, but they just are lacking compared to most of the cast.
He also has plenty of bad MUs: Fox utterly destroys Link [beats him in neutral and a technical Fox probably wins the punish game too, given how waveshines can't really be escaped by SDIing out... if the Fox can actually pay attention while waveshining and reverse directions as needed, every shine leads to a stock or Link on the edge. Also Link has literally no offensive answers to drillshine shield pressure, although I'm probably going to look into seeing how intentionally jumping into shine changes things, based on some stuff M2K said at the summit about shine pressure related to Sheik]. Falco beats Link handily, and people think Sheik does too [although there's some interesting stuff about that MU that might make it not so bad]. Falcon bops Link pretty cleanly and Marth Link is even or possibly favors Marth slightly.
Link then has a variety of MUs that I'm not so familiar with, but losing to half the Melee top tiers, and the best character in the game badly, is definitely not the ticket to being a top 10 character. [I've he also loses to Diddy Kong, ROB, ZSS, Mario, and TL, though I can't confirm or deny any of those]. One of his saving graces is that he is supposed to beat two relevant high tiers - Samus and Game and Watch.
In the end, I think Link is a better character in PM than Melee, but he's probably in about the same position on a PM tier list as a Melee one if you compare them [mid-low in Melee at like 18th/26 vs probably in the 30s in PM's cast of 45 or whatever it is].