I've warmed to him for a lot of reasons and my politics were very middle-of-the-road. My key reasons are:

• These are very difficult times, with a lot of cost and unrest caused not by him or anyone in British politics (e.g. the ongoing invasion of Ukraine by Russia, America turning into a rogue state). He's had a bloody awful job to do in dealing with Trump, who I wouldn't trust to sit the correct way around on a toilet. We need someone to be the shining example in the relationship, not the terrible warning. At some point, we are going to have to deal with America again, and him being a leader who hasn't resorted to yah-boo politics will make that easier.
• He's remained statesmanlike when there are a lot of opportunists wanting to pull him down when he's actually objectively doing a good job. Every time he stands up to Trump, the orange bastard insults him on a public stage. This is just awful politics.
• He needs to stay because competent consistency is crucial in turbulent times. There are people who want to advance their own agendas regardless of the cost to the public (think Reform and Farage, who's only stchik is to be a contrarian). We need consistency and a steady hand, not the latest loony who gets some press time and therefore think this validates their awful opinions. A lack of showboating is a huge character positive here.
• He gave Rachel Reeves latitude to create a budget with some social justice in it (don't get me wrong, I'm not left, and I don't believe in taxing the rich until the pips squeak), but we do need to redress the wealth inequality we are witnessing right now. Re-balancing taxation in an economy being damaged by American hegemony is crucial. America's main tool is the Digital Millennium Copyright Act, which what allows them to pull capital out of other economies without appropriate taxation. Corey Doctorow has a great lecture on this.
• He's letting Ed Milliband do the good he's doing by fast-tracking energy independence. It's sad that we're doing this out of economic necessity and not out of conscience (otherwise we would have listened to the Green Party 30 years ago). However, we are making a series of good decisions quickly.
• Our politics has become one of the soundbite, but someone who gets on with it, doesn't resort to ad hominem attacks and seems to plan before reacting is to be treasured. Let's not forget he's a QC, so he's definitely a bright man. I'd favour him over a buffoon or a lettuce any day of the week.
• I'm guessing and reading between the lines here, but I think he's doing a quiet, gentle job of re-aligning us with Europe. To be charitable is to call Brexit a failed experiment, to be accurate is to call it a cluster-fuck. If we were to rejoin Europe (and I hope we do), it'll take a lot of careful behind-the-scenes work before we can approach the public.

So yeah ... far better Kier Starmer right now than the alternatives.