They’re charging you for what travel agents and their call centre can do for free so not really.
Obviously I’m a bit biased because it’s my profession but generally speaking -
If you’re doing a simple one-way/return trip, booking with an airline directly is usually fine.
I would advise against using an online only travel agency though (basically anything through sky scanner that’s not airline direct)
If you want anything special such as round the world, multiple stops, 2 seats for 1 passenger (very overweight people need this), are travelling with more than 10 people, are prone to mistakes, are a frequent traveller (travelling more than say 3 times a month) have certain fare rules required, want to make a reservation without paying straight away, would like to book onto a sold out flight (it’s possible), booking tiny airlines, travelling to an obscure destination, would like to book more than 1 airline on your trip, are a business owner who travels or has staff who travel frequently, would like to travel in a premium cabin in one direction but economy in another direction (this is one of my favourite tricks and it makes flying business classs MUCH more affordable and realistic for most people) then a travel agent is probably a good idea.
A few constraints is that travel agents cannot redeem airline points for bookings and we are bound by the fare rules more strictly, airlines can break their own rules if they want but it would be rare for them to let a travel agent break their rules (unless you are a corporate client then they will usually give travel agents free reign to keep the company booking with that airline). You earn airline miles at the same rate as booking direct with an airline, it just depends on which fare you book onto.
But the key point is to find an experienced travel agent that you like, which is hard because people who have experience as travel agent almost never stay in retail (and no one likes everyone). It pays too little. Experienced agents usually move to a corporate agency or into travel wholesale work.
Also airlines pay really low commission (no commission in the US) so retail agents will probably either charge a booking fee, mark-up the fare (I’m not a fan of this practice) or ask you to book accomodation or something at the same time to make it worth their while. So it depends if the fee is worth it,
if you are booking a round the world trip even a fee of $18,000NTD would be worth it with a decent travel agent as One world and Star Alliance round the world fares are ridiculously over priced and any experienced travel agent should be able to find a reasonable alternative for about half the price of those fares.
Pricing gets a bit complicated and also depends on the country/agent/airline/travel agents company but generally speaking there should not be a significant price difference between booking directly on an airline’s website and booking with a travel agent