Most actual services are pretty good these days. It's only really the customer service that counts when things go wrong with the product, and that is now quite rare.
Also many real faults turn out to be Openreach anyway, that the CP can do nothing about.
As for Zen and IDNet, I think their high (if the still are) CS ratings could well be people just defaulting to five stars, having not used it for years. I even ended up dissatisfied with AAISP who just refused to accept the stats I gave them over a prolonged period when my line had been banded due to a faulty router which I replaced.
There is an Openreach engineer lives less than half a mile away, on a road I go along most days ....
My banding was removed easily without AAISP action, months after I gave up asking them. The timing of the call to the control centre being literally less than five minutes before my router re-sync'ed, so no coincidence involved.
Connections: OnePlus 8 Pro on Three 4+ (LTE)/5G and at home Three Mobile, with (Three)ZTE MF286D router giving about 113/20Mbps.
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The price of liberty, and even of common humanity, is eternal vigilance. (Aldous Huxley version of the well-known saying)
Were there none who were discontented with what they have, the world would never reach anything better. Florence Nightingale (Cassandra: an Essay (1860 edition?)