LeBron's career divides into 4 sections, which correspond to his 4 teams:

2003-2010: Young rising superstar on a bad team

LeBron was a very good player for most of this time, but wasn't truly transcendent and the MVP until his last two seasons in Cleveland (2008-2009 and 2009-2010).  Even then, his team wasn't very good.  They made the Finals one time (and credit to LeBron for that, the team wasn't great), but went through one of the easiest paths ever to make it there and were promptly swept.  They also only made the conference finals one other and as the #1 seed they were knocked out twice - one in the conference finals, once in the conference semis.  This was LeBron being a great player on a bad team and not achieving team success - something we've seen from many other good young players.

2010-2014: Co-leader of the Heatles

Without team success, LeBron went and paired up with Dwayne Wade (a top 10 player who had already nearly single-handedly won Miami a title) and Chris Bosh (an underrated top 15 type who history underrates because of his role in Miami and his eventual health issues).  With 3 of the top 15 players in the game, not to mention vets like Ray Allen and others playing on the min, LeBron James had a supporting cast on par with those of Jordan.  And then he was finaly able to win nearly like Jordan as well.  2 titles in 4 years.  Undoubtedly the 2011 Finals is the darkest stain on his legacy though, when he (+Wade and Bosh) were largely outdueled by Dirk Nowitzki (with some help from 37 year old Jason Kidd).  LeBron averaged 3 points in the 4th quarters of this series, and his difference in scoring average from regular season to finals is larger than any other in history.  That beatdown by the Mavericks and the perception that he quit, as well as not being the clear alpha on the team are some of the strongest arguments against him.  Based on the talent assembled and the expectations that he created, LeBron's time in Miami was a mild disappointment, even with 2 titles.

2014-2018: Redemption in Cleveland

After ultimately disappointing in his first two stints (lack of team success in Cleveland, inability to match high expectations in Cleveland), this is ultimately the strongest portion of James' career.  He returns to Cleveland, where he's once again surrounded by two top 15 talents (Kevin Love was an All-Star starter the season prior and on the US Olympic Team) and drags them through a still weak Eastern Conference to 4 consecutive finals.  Overall, the Cavs go 7-15 against the Warriors, but do manage to win one of those to finally bring Cleveland a championship.  After LeBron's departure the team falls apart, but it's also worth noting that they lost Kyrie for an ineffective Isaiah Thomas (who they quickly thereafter packaged for Jordan Clarkson and Larry Nance) and Kevin Love was injured for most of the season.  This wasn't a team that lost LeBron and cratered - this was a team that lost LeBron, Kyrie and Kevin Love in exchange for Jordan Clarkson, Larry Nance and Rodney Hood (all career backups).

2018-present: Lakerland LeBron

After being surrounded by elite talent for most of the last 8 seasons, LeBron is finally placed in a position where he doesn't have established superstars around him - and promptly misses the playoffs.  Part of this is a result of injury and the overall youth of the team, but it's also worth noting that several players (Brandon Ingram and Lonzo Ball) blossomed once they left LeBron's team.  So the Lakers promptly went out and got another top 8 player in Anthony Davis, which leads to another Finals victory.  This is probably LeBron's most impressive finals victory yet - and the only one he wins without having a high level star third banana. Danny Green, KCP and others help, but this is pretty much LeBron and Anthony Davis.  And then of course we all know what happens when he's left without Anthony Davis in the playoffs this season - first round flameout.

Bottom Line: People want to give LeBron credit both for playing with bad teams (true from 2003-2010 and in 2018-2019) and for winning titles (2012, 2013, 2016, 2020).  Looking at that it's impossible to give him credit for both simultaneously.  LeBron has played on bad teams early in his career - and had a bunch of early playoff exits.  Beyond that, he's hand-selected his teammates and only had 1 really bad supporting cast - where they failed to even make the playoffs.  And LeBron has won titles - but never without another top 10 player and generally a top 15 third guy.