They were effective against the strains circulating at the time. They probably also helped protect against hospitalization and death even in those that caught it.

You are correct, to the extent I investigated they is no hard evidence for _any_ vaccine working. Somehow things are manipulated to give the appearance of it being effective. Example: In the Pfizer COVID vaccine trials both placebo and vaccine groups fell ill at the same rate, however since the placebo group group showed more COVID positives in the PCR test ( a dubious test), they arrived at the 95% effectiveness rate. The way 95% was calculated is also a complete travesty of commonsense. At this point I'm not even sure if any data is real, or completely made up. If I recollect in flu vaccine trails they check for antibodies in the participants, not actual incidence of the flu.