That was an untapped market and their needs were unmet until funding. Now you will only see that kind of growth from a new untapped market from a different founder type that was also underfunded by investors (and thus choked off their most ambitious still unsolved problems).

I’d guess lower willingness to take risks due to the rising costs of housing, food, etc

Probably control. Those who succeed don't want competition and fixed it so they are the only ones.

toC -> toB

The smartphone revolution which enabled many of these tech companies is on the maturing side of the lifecycle. It will come back around again when the next enabling tech favors quick decisions and new thinking with fewer hard skill requirements.

very confident this is the answer: the opportunity cost of starting a startup increased. Top tech companies have vacuumed most of tech-minded working class talent. And can you blame them (me)? the risk adjusted returns of wage labor is simply much higher.

My humble POV. Stuff is getting so much more costly. Risk appetite has reduced due to macro economic situations.

Maybe exploring the possibility of starting your own businesses entered the minds of more seasoned professionals as startup culture was normalised. We just have a wider range of founders now!

Without looking at other responses, generational waves, timing. Maybe this observation helps explain superstitions like the Chinese Zodiac 12 year cycle.

You got older.