So much depends on the local depot and individual drivers for UK deliveries. Both of these couriers are good in my area. That said, I sympathise completely because Hermes/Yodel makes my heart sink too!
With international service, so much depends on the 3rd Party they hand off to for the final leg of the journey. USPS and Royal Mail are relatively dependable, but many countries are not so lucky.
Also delays are usually down to Customs clearance time which is long for some countries (Brazil comes to mind, and US with the tariff fiasco) especially if the Buyer didn't provide their obligatory tax ID number. Luckily using tracked service protects you and helps Buyers wait more patiently, as they can see what the hold up is.
