What happened to Jungle-Entrance Covering?

This thread is about a pattern my buddies and me have been encountering more and more frequently over the last 1-2 seasons. What "covering" means (for those who might not know) is that you buy your starting items as quickly as possible and then rush to your side of the river with the objective of placing a yellow trinket ward at the entrance to your jungle (or mid-river bush) to spot an invading enemy team. I can remember that when I started playing League in S4, I was always told (and pinged) to "cover" jungle entranecs before going to lane. This is especially important for the mid-/ and botlaner, since this i where most of Lvl1-invades happen. But now I rarely see this being done by my mid/bot-laners. And sometimes we do get invaded, give up a kill and maybe even another one or two flashes. This is almost always followed by a "gg mid, thx for giving a kill to <<insert enemy midlane champion here>> by the very person who did not help covering the river with a ward. Agreed, 1 kill might not decide the game, but it gives an early advantage, sets the tone of the game and may even pressure your jungler to start elsewhere, losing time which may have severe effects on lane-pressure.

I am now playing on Gold/Plat-level. Back in S4 when I was playing with mostly Bronze/Silver/Golds this was not the case. In 99% of games people were covering immediately at the start of the game. Have players become lazy? or do they not care anymore? Has this LCS-level of earyl game knowledge gotten lost over the years?