Not impressive.

It doesn't work this way, but perhaps Britton thinks this is an refreshing display of self-awareness and humility?:

"Britton spoke to Boone in the wake of giving up a walk-off, two-run shot by White Sox All-Star shortstop Tim Anderson in Chicago's 9-8 win over the Yankees in Thursday's "Field of Dreams" game in Iowa.

'I told him I don't deserve to be out there in the ninth inning; other guys deserve it,' Britton said Saturday before Game 2 of the Yankees-White Sox series at Guaranteed Rate Field. 'I haven't been pitching the way I should be to be out there when the team needs wins. I told [Boone] I want to pitch, whenever you need me I'll be ready, but I don't deserve to be out there in those situations.'

Subbing in as the team's closer, and put in charge of the ninth inning with Aroldis Chapman on the injured list due to left elbow inflammation, Britton has had four save opportunities and converted only one. Britton has an 8.10 ERA in those four appearances, giving up three earned runs over 3⅓ innings pitched."

...

"Britton has been dealing with command issues, which he has attached to his routine being disrupted by missing spring training to undergo left elbow surgery. The 33-year-old also hasn't completely recuperated from suffering major weight loss after contracting COVID-19 in the offseason."

"Command issues" is an understatement. Fourteen walks in sixteen innings. 

I don't think it's just his "routine being disrupted," or a physical glitch. 

He has always bean a crafty lefty working the corners and unwilling to throw a pitch down the middle of the plate. But there are times when you have to throw a strike. Like when it's the bottom of the ninth and you're up 0-2 on a #9 hitter and the next batter is Tim Anderson. I think it's a strategic and mental problem as well as a physical problem.

Then when you beg out of closing, I think it's very fair to question your nerve.