As for business travel, I guess it depends on how we're classifying that? I know a couple of doctors who travel to a couple of conferences each per year. There's a lot of socialising in places like Las Vegas, Honolulu, Maldives, etc. I know board members attending their international board meetings twice a year in places like London, Washington and Johannesburg. Lots of folk going to trade fairs... the day might be looking at new products and being wooed by suppliers, but the evening is spent socialising. I doubt public servants do any of those things, but even if they did, it's not fair to say they're the only ones!
I think business travel is going to change quite a bit, depending what it's for.
I'm sure the conference market will be trying hard to resume face to face conferencing. Honestly, electronic conferences are not very interesting, and it makes a poor speaker into a totally boring nightmare. In truth a lot of the value of the conference is in the connections made with others - people who might work with you, potential clients and even intelligence about your competitors. I have done a few on-line conferences, but have not managed to get that personal connection stuff happening.
Also, I am sure that self funded travel such as that by doctors, lawyers and other professionals to conferences etc was always at least partially driven by tax deductions. I suspect those people might continue to travel. I have noted that a lot of orthopaedic surgeons have conferences in the northern hemisphere ski fields in January!
Other business travel might be visiting regular clients. This can probably be managed on zoom, but it really only works if there is an underlying relationship that was probably developed over some years face to face. In some cultures, this is even stronger. I think it will be pretty hard to open up new business relationships exclusively over zoom.
I do think that internal travel such as for internal meetings etc might well be seriously reduced as everyone has just learned to suck it up and do it on zoom. Still, it makes it hard to meet new colleagues and form relationships, and have private off the record chats with people etc.
Finally there is training - there was a whole thread about how cough training is via on-line methods and how people are craving for face to face training. This is my business, and it is certainly true that people do not want to do 5 days training on government procurement via zoom!