In the last 3 days our 25 Mbps NBN HFC connection in Leeming WA 6149 has been useless. Constantly dropping out too slow for Fetch and any internet use. Supposedly there is no outages in my area. I suspect that the HFC network is unable to cope with even the current customer base. Any reason why I can't go to month to month so I can decide month to month your internet connection is actually usable? To be honest this connection has been poor since day 1 and I can't see it getting any better anytime soon maybe I should just contact the TIO and get the contract cancelled.
Optus indicates expected speeds should be 15Mbps in peak hour and 23Mbps at other times.
If you are getting consistently below this then you shouldn't need to go to the TIO. If Optus can't fix the issue then they should be ok to release you from your contract on request (Legally they're required to).
Note that the NBN is currently redoing all HFC connections and that may create a temporary drop in performance before it starts performing well again.
If the speed drop is mainly in peak hour then its probable Optus are not purchacing enough bandwidth for your area.
If the issue is constant then changinf providers may not resolve anything, although other providers do have a better reputation for resolving these issues with the NBN.
PS Just my opinion but 5G is unlikely to be the panacea some think it will be. Data will be pricy and performance indoors dire. And even though its been announced for 2019 rollout it still doesn't work well in the laboratory. Just my 0.02c