First off, don’t be disheartened.
I feel that Zwift does penalise slightly aggressively based on weight; IRL I can hold my own against my other rider friends, but on Zwift I just watch them fly off as they have a 10kg advantage over me.
I think what you’re experiencing is really several smaller issues all gang up on you. In ZRL, it’s an even more exacerbated problem.
In the three seasons I’ve been riding it, I haven’t got a single FTS or sprint point and - across our team - I think we’re averaging a handful of points a race.
In most races, the issue is that intermediate sprints don’t just exist in isolation; I would probably score more points if the first FTS was 100 metres from the starting pens. I find it’s hard to even be in contention because the pace beforehand means that by the time we reach a sprint, I’m already well down the field, or not in a big blob where I can leapfrog off the group pace.
The second issue is that standards have - I think - really shot up year-on-year.
In Sprint 2021 we were hovering around 3rd/4th in our division.
In Autumn 2021 our same team, with arguably a bit more racing fitness in our legs, was down in 10th/11th.
My conclusion is really that weight is more of an influencer on your success that your raw power development. In that, you could be 20% more powerful than the average rider, but if you’re not light enough you’ll still get chewed up.
FWIW, I don’t think sandbaggers are really that much of a problem in ZRL compared to general community races and events.
As to what to do about it, other than the obvious answers, I think you need to break the challenge down. Forget about ‘getting a result’ in the race overall and instead work your work up to sub-goals, which is what I do/did:
Goal 1 = Can you hold the main grupetto pace for 1 Lap?
Goal 2 = Can you hold the pace of the leading group for 1 Lap?
Goal 3 = Increase number of laps
Goal 4 = 20 mins
Goal 5 = Full race, but not contend the sprint
Goal 6 = Full race and be a contender in the sprint
I have never, ever been able to hold the leading group pace for more than 75% of a race - usually it’s 25 - 50%.
I can, routinely hold the ‘main’ pack pace for the whole race though
These days, I view a race as ‘20 mins’ and use the 20-minute power on ZP to gauge my progress. But it’s largely academic; I’m never going to make A category and I’m never going to win B category, so I just view it as good exercise in and of itself.