Were you told there would be a welcome pack? Is it something AirBnB says all hosts must provide?
There are a number of issues here; firstly welcome packs have never been universally provided by self catering establishments. Therefore you might well be disappointed if you expect one, in lots of locations before Covid and during it.
Secondly, it doesn't matter if there is serious risk from these items, as a PP said, steps beyond what are necessary are being taken to ensure those who are most risk averse and frightened of things can feel comfortable and also to provide as much protection as possible to hosts. It might seem like cost cutting and sometimes it might be (and bearing in mind these businesses have often incurred lots of extra Covid costs and drops in revenue, you'd expect sensible cost cutting steps....it's just business sense) but often hosts are complying with instructions from the organisation they are part of. AirBnB probably tells its hots the regulations it has to meet at the moment. They attract customers by being able to say certain requirements will be met during Covid by all hosts to give certainty to customers and this attracts more people...so then the hosts have to comply.
It is irrelevant whether people think the measures are sensible or whether they would or woukd not use a welcome pack provided. And the fact that other organisations provide one isn't that relevant either. Premier Inn is a hotel which is very different. Items are centrally bought in and put into rooms by staff who are doing lots and lots of rooms - this is their job. People hosting from Airbnb are householders and it is harder to ensure standards are met in terms of where welcome pack items are sourced from, who has touched them etc and this will cause customers who are anxious, more anxiety.
Op, are you someone who objects to Covid measures and policies generally and thinks they are too extreme and this is just one example of this feeling? I expect if this has made you feel cross, there are lots of other things, but the reality of living in a pandemic is lots of things will change that you probably don't like.