You are dumb.
LoL has been heavily modified during pre-season. Champions are not rising because of "sudden popularity".
was average at best during S5. Pre-season gave him
and Fervor of Battle (overnerf right now, but buff next patch) and this is how his popularity has risen. Also, E changes helped him too.
has been buffed but he also super-synergizes with the new masteries and this is why he is now strong.
is atm very strong because of how much garbage
and its variations are. Also, Thunderlord gave him extra-burst which is very handy against squishies and Grasp of the Undying gave him extra-sustain making him in either scenario, overall stronger. Also, AP items have been nerfed and as a result, many toplane champions cannot bully Malphite so easily anymore.
Yes, 2 seasons ago Malphite was "meh". But LoL has changed since then, champions were nerfed, items were modified and new masteries have been introduced since then. There is a reason why
is strong right now.