Actually I disagree. Judging players based on their important/iconic moments is just too volatile because they are just that - moments. If we replayed that moment 100 times, we don't know how many times those players would be able to replicate them.
If Lloris Karius/Marquinhos/Donnarumma doesn't pass Benzema the ball - the moment doesn't happen and that's it.
Also it's not like iconic moments are exclusive to all-time greatest players. Recently Kai Havertz, Kingsley Coman were players who scored in CL finals. Are they all-timers now?
If you watch compilation of best touches/goals from any given year, huge amount of them is made by completely random players from random leagues like J-League.
If I let random people play for 50 years in my home village they will probably produce one goal that will resemble the famous van Basten volley.
EDIT: Also, judging players on moments leads to bizarre situations, when suddenly Aguero is remembered mostly by a goal scored against a relegation fodder team playing with 10 men. Strange stuff.
On the contrary, a goalscoring record of a player spanning a whole decade is a much better proof of greatness. It's simply much more solid and much less volatile. Also, in order to win a league, a team needs to regularly beat bad and average teams from said league. Goals against such teams are not unimportant - they are key to lifting the trophy.
Most, if not all, teams in the world would kill to have a striker who's always available and who guarantees beating average and bad teams every time. So I don't buy the argument that only the select few goals from the biggest matches are important, while the rest are meh.
Let me just say that I will laugh my ass off if Lewandowski actually manages to beat those 27 goals in a single try, while playing in a team full of kids who never won anything, lead by a rookie coach who learns his job on the fly.