Spreading the talent pool too thin. The extra team in the competition, had an opportunity to pick the best players off contract, to the detriment of clubs looking to shore up their weaknesses.
The three byes distort the table, and take away another weekend game for the fans.
The idea that Sydney teams must lose two home games each year to "promote" the game, when years of doing this has not achieved any measurable increase in interest from new areas.
The refusal to invest in decent local grounds for clubs like the Bulldogs and Souths, so they have no home advantage, and no base for fans. The argument being that the money has to be spread into areas that the NRL wants to infiltrate, so older clubs can do without. So, give those traditional clubs a super stadium, and tell them to share it.
The NRL has lost its heart by pursuing growth for the sake of it, instead of focusing on quality.
Talent pool is a separate issue that is even a struggle when there were only 16 teams in the comp, however the NRL is not to blame for this. I'm sure you know Chris, each team manages their talent pools separately. Some teams choose to invest in their pathways (Cowboys, Panthers, Eels, Storm), some teams choose the top heavy approach and sign the best players on the market when they're available (Titans, Roosters, Souths, etc) other teams just sign average players to big money deals because they need bums on seats (Tigers, Bulldogs up until 2022, Dragons).
There is a talent pool issue, each club chooses to address that their way. You are never going to get a perfect balance. Covid did not help talent, but it's slowly getting back on track. This should have no impact on an expansion team nor should it dictate whether it happens. If NRL is that concerned, they would have to address this by scrapping the salary cap.
3 bye's is actually not because of an extra team, it's because of origin. The NRL made a decision to NOT go with SOO stand alone weekends, thus having to insert 2 extra bye's during origin period to ensure players are getting adequate rests. Without origin, there would be no need for byes. With an extra team, yes, there would be a need for 1 bye. This will be rectified with the addition of an 18th team in a few years when it's time to renew the TV deal.
With abovementioned point re: TV deal, this is all that its about. An 18th team by then would mean that not only do we play an extra round (9 extra games) but also another extra game per week so every week there are 9 games of footy over 26 rounds (do the maths). That means extra $$$$ in TV rights deal. This is how NRL will achieve expansion. Do they care about talent? No. Individual clubs should care about that.
Sorry but why the hell should NRL care about having a heart? It's a business lol.