It is impossible to say how well he compares to the entire field he’s faced in his fourteen years in Formula One.
But you can tell how well he compares to his team-mates. And from there, infer how he’d compare to those who’ve been team-mates with his team-mates.
Lewis Hamilton is a phenom, winning multiple national karting titles and a European one, as well as a number of open-wheel championships before entering Formula One.
But that goes without saying. You have to be a fantastic driver simply to get in the door.
Within Formula One, Hamilton has been paired with a number of highly-regarded drivers. In his very first year, he came within a point of winning the World Driver’s Championship against Kimi Raikkonen (a guy, who, until that point, was regarded as the best driver in the field never to win the crown). Even more impressive, he was teamed up with multiple-world champion Fernando Alonso, the guy who ended Michael Schumacher’s five-year WDC reign and denied Kimi those previous crowns. Alonso is regarded as one of the best qualifying drivers ever to turn a wheel in F1, and Lewis beat him in qualifying handily. They finished the season tied in points, though Lewis won second place due to having four wins to Alonso’s three. An impressive showing considering how many rookie mistakes Hamilton made that season!
(from Rally Stars, the original image at Race Fans is borked)
After Alonso came Hekki Kovalainen, whom Lewis absolutely crushed on his way to his first championship in 2008, then World Champion Jenson Button, whom Lewis dominated in qualifying, and whom he outscored in two of their three seasons together. (the middle season being Lewis’ worst ever against a team-mate, coming in 5th in the WDC to Button’s 2nd.).
After that, he left McLaren for Mercedes, where he was paired with Nico Rosberg, friend and former team mate. Now Nico is a feisty team-mate, and he dominated an admittedly over-the-hill Michael Schumacher (already in his forties) in their time together. Lewis beat Nico in qualifying, but not always by as much as his former team-mates. Yet it was apparent that, absent car problems, Lewis was dominant in terms of race pace, and was nearly always quicker in the wet.
In their fourth season together, Rosberg finally beat Lewis and won the World Driver’s Championship. Becoming only the second team-mate to beat Lewis Hamilton over a season, albeit by a pretty slim five-point margin. Lewis beat Rosberg in qualifying, overall wins and overall podiums, but had one more race retirement than Rosberg, which spelled all the difference.
Since 2016, Lewis Hamilton has been paired with Valterri Bottas. Their story isn’t over yet, but over three full seasons, Lewis has dominated Bottas in qualifying and races. Back in Williams, Bottas dominated Felipe Massa, a guy who, back in his Ferrari years, beat Kimi in their second full season together on his way to narrowly losing the 2008 championship to Hamilton. Not a slow driver by any means. Granted, he was in his mid-30s by then, but Valterri Prime is not beating 35 year old Hamilton like he did Massa!
Bottas is getting closer to Hamilton in terms of qualifying pace, but over race distance, Lewis is often miles ahead. And as seen in the recent Styrian Grand Prix, Lewis is still nearly untouchable in wet conditions.
So, Lewis Hamilton, over fourteen years, has only been twice beaten by team-mates, both of whom are World Champions themselves, and has consistently beaten three world champions, one pretty handy driver, and one pretty average (by F1 standards) driver over the other twelve years. His team-mates have, in turn, have beaten the likes of Jacques Villeneuve, qualifying genius Jarno Trulli, Felipe Massa, Haas’ Romain Grosjean, the infamous Pastor Maldonado and Racing Point’s current ace, Sergio Perez, all in similar machinery. That’s a lot of good talent Lewis probably would have beaten if they were in the same team.
Granted, Lewis might not be winning championships today if he were in a non-Mercedes (he might have won 2017 and 2018 in a Ferrari. Vettel was very close in those years), but he is the only driver to have claimed pole positions and race wins in every single season of his career. Even when he wasn’t in championship leading cars.
And sure, Mercedes would probably still be winning Constructor’s Championships without Lewis, but they may not have won so many consecutive Driver’s Crowns without Hamilton’s help. When cars are within 0.2 or 0.3 seconds a lap in pace, a driver like Lewis, who sometimes has an advantage of over half-a-second per lap versus his team-mates, is worth just as much as the millions the teams spend in car development between races.