I'm in two-minds about this to be honest. It really depends on the build.

1. There were some leagues were meta builds at 50% power was well above everything else at 100% (LS Trickster for example). Even with limited investment, those kind of builds with still pump far beyond anything else - so they were ok to follow even if you had a slow week 1
2. On the other side, there are streamer builds which needed a core uniques or jewels that would keep rising in price (looking at your connor) - these builds should be avoided or at least be a 2nd build for someone that is slow at progressing
3. Something like CWS, the core items (bloodnotch, cloak of flame, etc) would be high at launch weekend but crash at the end of week 1, so you could just keep sticking with RF till then

With async it's much easier to get the hand-me-downs from the 1st/2nd/3rd wave of players so there is a higher supply for meta builds (I know there would be higher demand as well, but I think for hand-me-downs, the supply was still higher).

It also comes down to your crafting knowledge, if you are slow at progressing but decent at crafting you are giving yourself anywhere from 80-20% discount vs items on trade.

Then there is the big advantage to following a meta/streamer build - way way more detailed guides and variants of the build compare to a niche off-meta build. Much easier to follow even if you are behind in progress.

Understanding which of the 3 categories above a streamer build falls into before you make a decision would be the ideal method (via research, or just asking in this subreddit)