No but the reason why the EPL system works is that the cup system and relegation system come as a package as it gives every team something to play for right up until the final round. They either go hand in hand or not at all. If you had a first past the post rule in the NRL the way it currently stands half the fans would lose interest in the competition halfway through the season.
And the FA may not be an international competition but the UEFA cup is and that's also part of the reason there's enough interest in other parts of the EPL meaning they can get away with not having a finals series.
I see what you are saying but it doesn't necessarily work out like this. In the vast majority of seasons only the best clubs are left in the FA Cup near the end of the season, and therefore the people supporting the smaller teams only have avoiding relegation to look forward to (or nothing to look forward to if you are a comfortable mid table team).
I've grown up in the UK and I think the minor premiership should really be the champions of the sport as it shows who were the best team over 7 months, not 3 weeks. If we are going to keep the finals, I definitely don't think half of the league should be involved. Top 6 at the most (and ideally just top 4). If there were no playoffs and you asked newcastle fans how good their season had been, they'd probably say "disappointing" or "mediocre", but they were rewarded with a spot in the playoffs and would only have and to play really well/be really lucky for 4 games to be champions.
The most respected playoff competitions in the world are probably the NFL and MLB, and in these competitions 6 out of 16 (about 33%) and 4 out of 15 (about 25%) of teams in each conference make the playoffs. NBA (like the NRL where 50% of teams make the playoffs) get laughed at and people say "its harder to miss the playoffs than to make them". They are also losing ratings (like the NRL did with the manly and melb games in the first round).
For a no-playoff system to work here (and using the regular season as champions) I think you'd need a huge cultural shift. People tend to go to games here when their team is winning and I've heard people say "there's no point me going cause we'll lose". That's alien in other countries which makes it possible to have teams with nothing still to play for filling their stadiums week in week out.
Note: this isnt a sour grapes post. I have no problem with the Warriors beating us. They were by far the better team.
i think there is just the broader argument of whether this system finds out the best team in a given year, or whether it simply finds out the team that peaked at the right time that year. Both are valid views.