As Raymond say you need good guild/friends that run lb to max efficiency of your energies.
Even with a good tier party the effort to reach plat tier was high. Just to speak about “easy” numbers:
28k points for plat tier means around 500 runs with a plat tier (I considered 50 point/run for easy calculations). To craft that amount you need 1500 essence. My personal experience is that you get around 12 essence/hour in tomb/huntlet. Means 125 hours running just for essence. This time is reduced running event, that gives you a fair amount of essences from mobs/boss. So Let’s reduce that number to 90 hours. It’s 18 days running 5 hours/day.
So big effort in time.
Then you have to craft all that energies! In 2 hours you can craft 5 energies. Using a clock-alarm (as I did) each 2 hours you can craft around 35 energy/day. Will take 15 days to craft all 500 energies.
So.....tiers this year were challenging for non-plat users, requiring a huge amount of time and effort, don’t be surprised or sad if you weren’t able to reach high tier, wasn’t easy at all!!!!!
I was lucky I stored around 100 energy from last event and 80 essences, and that I had good mates/friends that boost me to plat tier, but took me around 2 weeks of hard work to do that, just for the plat vanity ( I love it!).

My suggestion for you as key factor to reach high tiers is to be in a good/active guild and to have really good friends that helps you out.

Good luck for next events!