Imperial Valkyries might not be winning, but they are getting closer to the male competition as seen when they went to overtime against FURIA. Naturally these feeder projects are gonna be very slow in terms of progression, but the fact that that female roster is getting a chance on stage against Tier 1 competition and putting up a good fight gives hope to the scene. You ask how much longer does it have to be like you're in a rush to see a GC match but it will take as long as it needs or until RIOT sees it as not feasible to maintain.
If we were to look at Valorant, sure, GC on its own is still a far cry from Tier 1/2. However, during the spotlight tournament, there were definitely some GC players who could shoot back very well. GC started in 2021 and the first championship was in late 2022 so it wasn't exactly the start of Valorant. In addition, this single tournament was 8-teams until this passing year which had 10 teams because the competition pool is still small. It's always gonna be more difficult to improve if the quality of your competition is limited and they're not incentivised to do better. EMEA GC at least has a good level of competition due to the amount of proper orgs invested into it. NA GC on the other hand suffers from only having at max 3 teams and one of those is a super-dominant team which is multiple steps ahead of the competition.
Lastly, there is a whole conversation that could be had about the scrim opportunities GC teams get which they usually do not get that much of. They don't practice against good competition and thus their strats are not as refined or deepened. You can compare this to how recently teams with academy rosters are improving a lot more because they have a consistent scrim partner that they can fully deepen their strats with. As a result, the main team and academy team prosper to do better in their leagues. If GC teams had the opportunity to scrim their Tier 1/2 counterpart, we would see a huge jump in quality, but right now, they are perceived as not worth it.
To summarise that last point for you since I know you're gonna cry about me giving you a proper response, GC players definitely need to improve their mechanics and grind ranked to be on par with Tier 1/2 at the most foundational level of the game. Then they will get the scrims to improve strategy so that they can compete properly. How long that will take is again up to the players and Riot.