Edit: also want to add that no one thinks Lebron James is having a hand in setting ticketing policies whereas Taylor Swift probably has someone asking for her input
Ticketmaster has exclusivity contracts with venues. You cannot bypass them unless the venue and ticketmaster want you to. The very nature of the exclusivity contract prevents your startup idea. Unless they are also scalpers in good graces with ticketmaster, there's no tickets for them in the first place.
For example in Scotland the main company that runs all the 'big' events is DF Concerts & Events who are owned by LiveNation who themselves are partially owned by TicketMaster. They also host festivals like 'T(ennents) in The Park' and 'TRNSMT' and own their own venues like 'King Tuts Wah Wah Hut'.
LiveNation also own many venues around the country.
Basically you're stuck with them.
I find it's relatively easy to get tickets though. Presales (through Spotify, DF concerts themselves ('gigsinscotland.com' and Spanish/Telefonica owned telecom company O2) or just being fast on the website is normally good enough.
There are other companies in the UK that run ticketing sales too. SeeTickets is quite big and the Ticketmaster owned TicketWeb. Both give better chances of getting tickets.
LiveNation is the promoter of every major artist and tour. When that merger happened Ticketmaster gained the ability to basically block any Arena Size artist of going on tour if they weren't using Ticketmaster.
EDIT: Also, I'm going to throw out there that I've heard rumors in the industry where if a venue doesn't get the percentages they're looking for from the artist, they'll scalp the tickets themselves obfuscated slightly.
What does that mean? Not selling out the venue?
Competitors show up once in awhile. If they see anyone with improved technology, they buy them. Otherwise, they have the market power to box competitors in.
The only way they will ever lose is if some sort of regulatory action made it impossible to get exclusivity agreements.
Taxis are the most overrated cartels. In most geographies taxis were just conduits for Medicare/Medicaid money who also gave rides to drunks and to the airport. Ticketmaster has more control of the market, and has it on a national scale.
There's a misalignment of incentives for most events. The performer gets paid for the show regardless if there's one attendee or it's a sell-out (some acts do share in gate and/or merch). They want the lowest ticket prices. The promoter is on the hook for a lot of fixed costs so they need to sell enough tickets to break-even; everything beyond that is profit from selling more tickets or higher prices. The venue gets rented but then TM "offers" them a per-seat fee in exchange for exclusivity. Then TM gets big processing and assorted fees for every act. Then resellers, legit or not, buy blocks of tickets that they resell in a dynamic market, prices floating based on demand and timing. Now we have TM coming back and saying "we'll offer you a marketplace and make it easier for you to secure supply (via bots and other shady processes)".
Trent Reznor of Nine Inch Nails fame has been doing this as part of his fan club for over a decade, and is a vocal opponent of scalpers [2].
[1] https://www.quora.com/Why-cant-I-resell-my-air-ticket-to-som...
[2] https://www.google.com/search?q=trent+reznor+ticket+scalping
Source: I have a ticket for NIN that I bought on Stubhub.
Then to prevent resells, would need an app with ticket barcode that changes over time, like most 2 factor auth apps. This should help prevent resells via printing and screen shots. I expect that's not foolproof, but could prevent the easiest alternative market. This would work offline too which is a plus since service at big events is generally bad. Could also make transfers as easy as venmo through the app.
The whole idea is to remove incentives from resells and make it easy as possible for people to transfer legitimately.
No resales, get a refund from the ticket seller if you can't go.