Lots of these threads don't seem to make a proper comparison. From a purely financial point of view discussions I read here on this topic are often so simplistic as to be meaningless.
Homeowner occupiers have to pay for maintenance, upgrades, repairs, buildings insurance and also when purchasing conveyancing and stamp duty, not to mention them only paying a mortgage on X% of the property value because they have put down a desposit, so it's not equivalent to somebody paying rent which of course will be higher because renters are paying for the use of 100% of the property. You can't simply compare a monthly rental fee to a monthly mortgage payment and believe it is a direct comparison when that is clearly not the case at all.
Landlords are taxed on revenue as though it were profit and still need to pay all maintenance, insurance, safety checks, letting agent fees, energy compliance certification, buildings insurance etc. Most BTL mortgages are also interest only therefore the "paying off someone else's mortgage" thing that always gets asserted is in most cases a fallacy.
That said, there should be very clear and robustly enforced laws to ensure all rental property is maintained to an acceptable standard which much of British rental stock is not (including quite a lot of social housing). Sadly this would raise rental costs further, though.
Tenants should have stronger rights in some areas but in others it's clear that landlords are exiting the market partly due to it being so difficult and expensive to evict nightmare, non-paying tenants who trash their properties. Perhaps there need to be much harsher penalties for that and swift eviction for non-payment, with court fees charge to the tenant not landlord, but better protections for long-term tenants who pay on time. Maybe separate rules for those whol wish to let their property on a short-term or annual contract basis and those who want long-term tenants with the contract terms being explicit on this, so both parties can make an informed choice (as some people do want shorter term rentals and some don't).