It's unfortunately true with a ton of things: hotels, rental cars, etc. Taxes, franchise fees, other taxes, facilities charges, etc. can all add on 20% or more. Especially if you're comparison shopping, you really need to verify whether you're looking at a base fee or the final tally.
Airbnb does this all the time. Their advertised prices don’t include cleaning fees.
If Airbnb included those fees the pricing would often come out higher than a hotel in many cases. And hotels include cleaning costs as part of the nightly rate
If you search for a certain date range, Airbnb will calculate and display the full price for each property on the SERP. It makes sense to compare asymptotically when you don't know the length of stay. The cable and telephone companies billing practices on the other hand are purely deceptive with no utility for the consumer.
Resort fees aren't new. Perhaps they've become more common but I haven't noticed. The more common issue with hotels, which isn't really their fault, is you might have 5 different taxes added to the bill which can add up to a good 20% of the total bill.
I think requiring to advertise full price is even more market friendly than sneaking in more fees. This just incentivizes dishonest behavior. It’s hard to advocate against such a rule. The US health system is also in dire need of such a rule.