One of the biggest problems I have never seen a good solution for is the levels of specialization.
The trades are an ideal scenario for unions and collective action. The work overall is standard and people inside a tier are mostly interchangeable. You need a water heater replacement, or a light fixture swapped, or a stone fireplace built, there are standards for the work and you can create standard pricing.
It is less true in our industry. Creative fields struggle with assigning value, and individual skills are rarely interchangeable. Some roles are more able to get clustered, “gameplay engineering in Unreal with x years experience”, but then details matter. Physics? Audio? Networking? Build tools? Graphics? Systems engineering? Throw specialties in there and it gets a little more complex. Add in the work that is not standardized, and you get even more complex in how to evaluate and assign rates and wages.
People in tech companies are less interchangeable than trades. The lists of major tools and technologies are quite long, and even someone who is an expert at making games in a platform or system can go to a new environment, look around, and realize they know little or nothing about the tools on the new project even though it uses the same base platforms as their past experience. They have years doing it with certain tools, but the company uses a different api or language or toolset that doesn't relate.
Big companies are different from mid-sized and smaller business and startups. The work being done varies tremendously. Pay scales and what companies can afford varies, laws vary by location. Demand and expectations vary by role and experience. Scope of work, difficulty of individual differences in work, and people's history all matter.
There is also supply and demand, people in demand who know it can often command much higher wages and benefits, something that movie guilds have worked out with agency rates and negotiated rates. It is not worked out in our industry.
There are plenty of problems that a union or guild could help with, but they also have many difficulties they introduce which don't have good solutions yet.