The customer base on M1 is larger and more likely to be interested in upgrading. The M1 Air was only discontinued in March and is still for sale through Walmart and Costco. Not to mention the resale market created by all the people that moved to M2 and M3. There are tons of M1s out there. It is probably the most relevant comparison they could make, even though we're accustomed to seeing previous-gen benchmarks on everything.
Sadly these days it's a waste to upgrade a single generation. There's very few workloads that work poorly on gen x-1 and work well on gen x.
So while frustrating to people that want to geek out on the tiny details, the real market for Apple is people not using Apple silicon and maybe the M1 users. Upgrading from M2 or M3 isn't worth it. Thus the comparisons with Intel Macs and M1s.
I like the M1 comparisons. They got some free improvements from the x86 -> ARM transition but everything past that is on them, so it's interesting to see how far they've come.
But that aside I agree it feels like marketing slime to tout improvements over 3 gens ago. At least include comparisons to last gen. Preferably with numbers on the chart.
There are a few such comments here already!