man x | grep -P y -C 3 | less
...is my standard here (-C 3 includes the pre- and succeeding 3 lines). For all the delights of CLIs, man pages are by default opaque walls of text. And dear lord the number of regex variants... - at this point, if at all possible, I'll avoid application-specific flavours entirely, and just pipe to grep -P (perl-style regex).I might suggest, however, that image/video manipulation is a case for which CLIs are uniquely unsuitable.
There surely are better ways (as you mentioned, Powershell appears to be a step or three in the right direction, though I have little familiarity with it), but it seems as though the greatest difficulty is in maintaining full backwords compatibility, while still encouraging new applications to make full use of novel features - not to mention the effort of modifying old applications to fit new standards that would need be expended.