Out of interest, I just looked up the first flight records for the Sport Aircraft Builders' Club (SABC) based at Serpentine in WA.
The first recorded homebuilt to fly was in 1967 (Jodel). The number of first flights for each decade since then are:
1970-1979 - 22
1980-1989 - 20
1990-1999 - 51
2000-2009 - 40
2010-2019 - 30
In 2020 there were 5 and from memory there have been another 3 or 4 this year. Obviously membership has also grown since the early days, and there are currently about 350 members. Quite a few of these are just social or associate members, so there are probably around 250-280 full members. As with most other flying clubs the average age of members doesn't seem to be getting any younger so the long term trend may be downhill. However, from those figures at least, while the 90's obviously saw the greatest activity, the current numbers are still quite respectable. Demand for hangar space is also high, so that's a good sign.