Erik Darling is fusing together queries like Dr. Frankenstein in his lab:
You may have noticed that both queries get pretty bad estimates. You might even be thinking about leaving me a comment to update stats.
The thing is that I created these indexes, which means they get stats built with a full scan, and it’s a demo database where nothing changes.
We just get unfortunate histograms, in this case. If I create very specific filtered statistics, both plans perform a key lookup.
I snipped this part because it’s so ingrained in DBAs that when performance is bad, updating statistics is a panacea.