What is the idiom or expression used to say that "what someone has done is nothing special"?

In the United States, I have noticed an increase in references to "participation trophies" or "participation awards" as an ironic way of indicating that someone's contribution is utterly unexceptional. For example, someone might say,

He's earned a participation trophy, anyway.

The implication here is that everyone qualifies for a participation trophy simply by showing up—so it has nothing to do with the effort or quality of the work that the person actually performed.

I believe that the notion of "participation trophies" as a meaningless form of recognition arose in the context of youth soccer leagues in the United States. Back in the 1980s, as youth soccer became extremely popular as a sports program in the U.S., there was a conscious effort in the movement to avoid the aggressive win-at-all-costs attitude (fairly or unfairly) associated with other youth sports programs, such as little league baseball. One way leagues tried to express this positivity and kid friendliness was with a surfeit of trophies, including (often) trophies for being on a team at all. Eventually the practice generated a backlash among people who regarded the practice as a symptom of coddling or anti-meritocratic behavior.

Wikipedia has this entry for 'Participation Trophy':

A participation trophy is a trophy given to children who participate in a sporting event but do not finish in first, second or third place, and so would not normally be eligible for a trophy. It is frequently associated with millennials. Their use has caused controversy: critics argue that they promote narcissism and entitlement among children to whom they are given, and are based on incorrect assumptions regarding supposed psychological benefits of self-esteem. Critics also note that some children also do not value them as much as they do normal trophies that are given to winners. Defenders of participation trophies argue that they teach children that trying their best is good enough, even if they do not win.

And Urban Dictionary has this entry for the related term 'participation award':

participation award

A "reward" one gets for merely participating. Although usually given with good intentions, more often than not it will remind the owner that he failed, and that his best is not good enough.

"Congratulations, here's a participation award, for doing your best!" "...because apparently my best isn't good enough to actually win something."

‘No big deal’ would seen to fit the ‘nothing special’ criteria but not so much the ironic messed up ask. You can’t really praise someone for messing up. Ironically you may say ‘smooth move’ but that would not directly mean nothing special. Side ways one could look at smooth move as nothing special.

Good luck.

This family of options seems to be close:

• unremarkable
• undeserved
• unmerited
• unearned
• unwarranted
• unimpressive

Some examples:

He got promoted for unremarkable sales figures.

She earned a 10 for an unimpressive performance.

My raise was unmerited, but I'll take it anyway.

“It’s like praising the postman for delivering your letters”

— Roy Keane.

This may be neologism but seems appropriate here.

Meh. It even has a Wikipedia entry now.

https://en.m.wikipedia.org/wiki/Meh