The postage options layout needs an overhaul. At the moment it is a mish mash that is confusing a lot of sellers and leading to the wrong postage options being used. 

The parcel size guide is basically the Royal Mail size limits in the first 4 categories smallest ascending - letter/letter, padded envelope/large letter, shoe box/small parcel, cabin luggage/medium parcel.

Now that under those categories eBay are showing the other courier options on that page it doesn't make sense.

For example, the maximum parcel size Evri allow is 245cm and that still applies to a small parcel (eBay's shoe box). If I was sending a snooker cue or a fishing rod depending on the weight I would still go into the shoe box option and disregard the Royal Mail limits that is based on because I know the specific carrier limits. Many sellers who are new to this are getting baffled by it and then further being confused by the carrier weight limits being shown under the selected service. For example again, Evri, pick a shoe box up to 1kg and further down it will say 'up to 15kg'.

eBay should be an expert in this area and see that it doesn't look right.

Removing the packlink legacy tool is also a mistake if sellers can't use a payment method other than PayPal or funds to pay for their labels. I need to show my postage as expenses on a bank statement and once the legacy tool goes it doesn't look as though I will be able to do that so I will be using Parcel2go and continuing to buy off the Royal Mail website instead of eBay. 

To be frank with you also, how can Vinted secure postage rates for their users at £2.29, £2.30 for small parcels and eBay can't get anywhere near that for their users?

This is intended to be constructive criticism. These things are putting a lot of users off and driving them elsewhere where it is simple to sell will less mental gymnastics required to understand postage, stay on the right side of very optimistic EDD's and when listing having to complete lots of item specifics and detail that isn't necessarily needed.