Is it reasonable to report to the council?

Seeking the opinions of landlords on this issue please.

I moved into a flat in January, landlord had bought it not long before and is a portfolio landlord. There were huge maintenance issues from the get go:
- plugs that didn’t actually connect to anything or work
- no hot water or heating when first moving in
- huuuuge leaks x 2 which meant I couldn’t use the shower for first month of tenancy
- evidence of damp started to show on one specific wall, landlord denied there is any damp at all despite it being evidenced with a moisture meter

It took a lot of back and forth with my landlord to get functioning running water, heating, hot water, and for the plug to actually work. He seemed irritated throughout. I reckon it took 6 weeks for it to be habitable. He refused to give me any rent reduction, citing repair costs.

Since then, the water meter continues to show a leak somewhere in the system and boiler continues to drop pressure. A thick layer of furry mould has grown on the porch ceiling from the water from the leaks. Downstairs has significant damage from leaks. More signs of damp are showing up downstairs. One contractor did turn up and said the entire roof needs replacing.

I have given it 7 months of my tenancy trying to resolve this informally. I’ve had everything from accusations that I was causing intentional leaks, threats to evict as the property is “inhabitable” to complete silence.

The landlord continues to instruct people he knows personally to come and do the work and they don’t turn up. I can count at least 8 occasions where this happens. Last week, I waited in for 2 full days for someone to come and start the work, they just didn’t turn up and no answer from them or the landlord.

I can’t think of any other informal resolution.

Is it reasonable to involve the council at this stage? What are the drawbacks of doing so?