He's not great, but the England job is a shit one too. So in that sense, I applaud him for managing some level of consistent results with a team that was generally picked by the media before he became manager. And he was pretty close to an unlikely (imo) trophy in the Euros.
I think the expectation of club level silky football is a fool's dream for England fans in general. You haven't achieved it in literal decades. The few teams who do usually manage to do that now have a core of players at one club - eg. Enrique doubling down on Barcelona's squad, every German manager and Bayern, and the only exception to that rule right now is France, who have an unparalleled depth of talent at the moment and can also switch to grind-out-a-result mode when needed. Southgate knows it's not going to happen, and that may suck for the fans, but it keeps him in the job.
Can you guys do better? Yeah, probably. But you underestimate how well Southgate has managed the circus around this job so he can actually do this job. Getting a better manager doesn't necessarily mean that aspect will get handled. So if you switch to someone else, you also need to contain the mayhem that tends to get created when that manager loses his first 2 matches.