It must vary by area because where I live in Kent, more often than not they will just not deliver your parcel the day they're meant to - and often they only let you know this fact late in the day as well. You have to wait a day, or two days later. Even if you selected a next day option on the website you ordered from ... they could not care less. It is literally impossible to speak to a human being in customer service (and I mean actually impossible) and they don't even have social media.
They also never, ever knock. I live in an apartment complex and they saunter in and dump parcels in the communal mail area (where parcels have been stolen), rather than walking 15 seconds more to at least leave it outside my actual property's door, let alone try knocking. One time they delivered my parcel to a totally different address, the 'proof' was a blurry image of white wall and the GPS the other side of town. The poor merchant I ordered from had to send me a replacement item free of charge.
I hate them with a burning passion and actually think they shouldn't be in business. Maybe it needs to be made law that the courier a company uses is listed at checkout - I for one would not make the purchase if Evri was the option and maybe that would send a message to the companies involved.
Not that any of that will happen, mind, and it will continue to be courier roulette with many online stores. 😭