just another extreme convergent evolution event … stuff happens …
No insects returned to land after adapting to aquatic habits
Due to different evolutionary rates or periodical changes in water characteristics, non-adapted terrestrial insects repeatedly invaded the aquatic realm with well adapted hydrobionts.
The proposed reason for the lack of land return is the character of numerous aquatic adaptations related to reductions, which are unlikely to be resuppressed
https://www.sciencedirect.com/science/article/pii/S1342937X18302971
and let me comment on this part:
… numerous aquatic adaptations related to reductions, which are unlikely to be resuppressed
and why not ? Nothing is impossible for evolution, look at this article:
Have wings come, gone and come again?
Can complex traits be re-evolved by lineages that have lost them? Phylogenetic study now suggests that wings may indeed have reappeared several times within the ancestrally wingless stick insects.