Hassle? What hassle? It NEVER has given me that over many years

It has a long history of being hassle. Really since it's initial release. Despite the name, it was never a true Norton product, it was created by Symantec after they acquired the Norton name and the (then) excellent Norton Utilities. It's always been a complete resource hog, and
nobody is daft enough to actually buy it with their own money from scratch. That's why (then) Symantec and (now) Gen (makers of the Avast AV suite) effectively gave it away for free to any OEM daft enough to take it (and believed in the case of the massive OEMs, to actually pay those OEMs to include it), in the hope that the less IT literate people will just renew the subscription when it ends. Generally, it is that type of clientele buying computers from those sort of companies.
As Symantec's/Gen's primary consumer product (Symantec made most of it's profits from their enterprise grade software, now owned by Broadcom), it's a hard business to be in when the freebie software is less intrusive, less resource hungry and infinitely cheaper. And in the case of Windows, included in the Windows install.
But enough of that, you have said yourself that is often pops up alerts. I bet the vast majority of these alerts are false positives. That's hassle. The sheer extra loading it puts on your PC is not only not green, it shortens the life of your hardware. That's hassle. The annual subscription - even iff free - needs dealing with. That's hassle, even if it's only one PC.
As for BT, they have 3 ISP brands - BT, EE and PlusNet - but seems to be struggling for how to place them in the market, particularly BT and EE, as PN sits fairly nicely at the no frills end of the market. This leaves BT and EE competing heavily at each other for the same types of customer, and with no effective coherent strategy, each including extras to make some small differentiation. Their previous strategy for the past 3 or 4 years was to make EE a consumer brand and BT a business brand, but as you've probably noticed from recent ads, BT is once again being pushed as a consumer brand, competing mostly with itself.
But it you like both the Antivirus product and your expensive ISP, I'm delighted for you. I won't be using either
