Ah well.
I used to have high regard for the BBC News, I preferred it and recommended it, then I got disappointed.
I used to have similar high regard for Royal Mail and thought the same as you, once avoiding Amazon for quite some time (15 - 20 years ago) because they used Securicor Omega and couldn't promise RM delivery. Today I hope the Universal Service Obligation is instead contracted to Amazon Logistics - their vans are up my street several times per day, seven days per week whereas RM.....
I wish investors who fancied owning a worldwide parcel company would just buy a worldwide parcel company, or build their own, rather than buying and pivoting a different business!
It's all about price (and who benefits from the profits).
Yes, Amazon is generally good- IF the item qualifies for Prime. They also have an interesting approach when they are looking like failing to deliver to schedule- i.e. when it's in backlog, it's flagged as lost and they refund quickly (they encourage you to ask for a refund then re-order, not wait). When you re-order, it generally comes in usual fast timescale. Works where items are dispatched from Amazon or Fulfilled by Amazon, but other items more variable.
Couriers are variable, and the scale of service within them varies. I occsionally deal with a business supplier who uses DPD on a high-cost tariff to ship costly stuff- and it arrives to schedule, and it's not chucked over the fence as they MUST supply a photo of the package in the door of the address WITH THE RECIPIENT in it. That's unusual, and costly. There's lower scale red DPD then blue DPD is the lowest tier. Not dissimilar with UPS, DHL and FedEx. UPS in particular have a top-tier service where it's guaranteed before noon, everything else left is delivered after that so it's a bit pot luck, if they are busy that day you'll wait longer for an economy price parcel. Then there's the "lower cost" options.... EVRI, Yodel.
The Royal Mail fit into more the "high end to mid range" in my experience. There are different services too- Special Delivery Next Day or Before Noon. Tracked small parcel services- 48 hr tracked, 48hr untracked etc. You pays your money and you takes your choice. They do relatively well due to experienced staff- who the management want to casualise. Not a good move. They also have the universal service obligation whereas other couriers can- and do-focus on a niche- B2B, secure packages, international, home delivery etc. (DHL and FedEx are unparalleled for international delivery- but oh boy, it costs).
Not just Royal Mail with a backlog at the moment. I am awaiting some fruit trees, the supplier lifted them on 23 Dec, but the courier didn't even pick up until 28 Dec and courier has said they won't start to clear their Christmas backlogs until next week. (He packs them to last 6 weeks in transit, sensible chap).
Re your last sentence
@Baxenden Bank, I sort of agree- but even more I wish that the govt had NOT privatised the Royal Mail but instead had put some competent and constructive (rather than aggressive) management in. Do we really want all workforces where everyone is on a zero-hours contract? We get backlogs when staff go ill or leave and cannot be replaced as it's hard work on zero-hours.
In short- delivery costs money. You can have reliable at a higher cost or cheaper at less cost. I just wish more retailers would offer more of a choice for shipping.
TPO