Here's why I say this. When you're a support and get an early tranquils or force or glimmer, your game becomes infinitely better and easier to stay alive in team fights, help out more in team fights, mobility around the map, sustain in lane and fights, etc. Which heroes are the most impactful early-mid game? Supports. If supports have farm, they'll be able to take over the early game setting up their carries for an easy farming game and catch back up in farm by the mid-late game.
Also this: let's talk about mathematics. If a support goes from 1000 networth to 2000 networth, that's a 100% increase in networth. If a core goes from 6k networth to 7k networth, that's a 16.7% increase in networth.
Now, you're all wondering "well if the support takes farm then my core will be less farmed than their core and will fall behind" and you're right, this is a risk. However, being behind 1k is not make or break (usually) and that 1k might be better shared with a support who can finish that early force staff or glimmer that can help the team, versus finishing that 3rd or 4th item on the core. Lastly, if that support gets that early 1k extra of networth, they should be more active around the map putting pressure on lanes and towers and therefore limiting the farm the enemy core receives and expanding the farm your core receives, eventually balancing out that 1k deficit incurred earlier in the game, but now you have a support that is 1k more farmed than the enemy support.
Long story short - we've all been there and losing out on a few last hits as a core is not game losing, but getting just 5 last hits as a support sometimes means the WORLD to them, those early boots, etc. Why doesn't the meta support a strategy like this?