Re: "you are bombarded with motorbike insurance advertising on every platform you go to"
Not really, just sign up to the mail and telephone preference services
The participation in these is subject to voluntary self-enforcement by the industry. That probably should not warrant any other comments.
As far as the junk mail - ignore it, systematically click "no offers" on any preferences and it will recede by itself in 2-3 years time.
As far as phone calls, draw BIG effigy of a middle finger on a cardboard and show it to BT. Moving off-BT to a SIP phone provider guarantees you the following:
You are now in real "preference" land. I really do not care where does BT leak its phone numbers to scumbags, but as long as you are on a BT line - you will get phone calls no matter in how many "no call" services you enroll (and pay for). Cannot really say about Virgin and others, but I would not be surprised if they are no different as BT wholesale runs BT phones.
The root cause is probably that the bulk rates call out scumbags buy have a significantly lower cost to BT numbers than to a 3rd party SIP provider which charges them the standard interconnect rate with no discounts. As a result any calls to non-BT blocks are firmly at the end of the queue (if in the queue in the first place)
I often get asked - why do I run my own PBX on a SIP line (especially when I used to work from home for BT - there was a point where my boss had the idea of administrative enforcement to take a company phone line). The absence of scumbag calls by itself is frankly a sufficient reason. So no f*** voice service from BT in my house. Ever.