I know my monthly usage pattern well after using my home fibre line for over 5 years.

If there's a 5G provider who can sustain over 100Mbps of speed even with weak 1-2bars of signal strength and priced at RM70-RM80, I'll not think twice opting for it because my 30M fibre plan is costing me RM105 per month which I don't even get to use much of it with most workdays out of home.

In Japan and many countries fixed 5G plans are now the trend, fibre plans are so yesterday.

There are no way to predict and avoid congestion with wireless plan. 
Because 5G is new now, plus there is a "entry fees" (+RM10 or 20~, or subscribe more expensive plan to turn on 5G addon), so 5G is low adoption now we cannot conclude its real performance.
Don't forget Malaysia is not using 5G mmWave, so it is actually mean 4G+ imo.

Other reasons like public IP, stability, torrenting... are the main factors that peoples give up wireless solution.

Very simple reasons, too expensive to build and maintain it.
Power consumption is 3x than 4g, coverage is 3x shorter than 4g. Mean 9x expensive to maintain as 4g.