Crashing planes, no mayday , whats going on ?

there has been a few unexplained crashes / no mayday / no claims by the usual groups / vanishing planes in the last year , whats going on ? whats causing them ?

is it

they are being shot down as a result of hijacks , covered up so no press to the hijackers cause ?

mechanical failiures ?

shot downd by ground missiles ?

collisions ?

wormholes / ufo / disgruntled pilots ?

i am ot making light of the situation , i am genuinely at a loss , and a bit concerned given the increasing frequency and the number of flights i do a year ......