Ronaldo's Portugal career being a dissapointment? Damn, he has set the standards so high that being the 2nd highest goalscorer in whole international football is being a dissapointment. He also has scored 9 goals in the EURO finals, which is tied for most with Platini. Those 8 times he has played in major tournaments is 2 more than Portugal played before Ronaldo, and that's since 1934. There was Eusebio back in 60/70s, then a big slump and the golden generation in early 2000s to till like 2008, when most of them retired and Ronaldo was only 22-23 during that time, with all the prime years of him coming. 2008-2010-2012 was all about Spain's golden generation and like 2014 WC, Portugal played that do or die qualifier game against sweden for a WC spot, 2 ties and score was 4-2, Zlatan scoring both of Sweden's goals and who else than Ronaldo scoring all 4 for Portugal. 2014 Ronaldo was injuried, it was never certain he would even make there and the fact is, that Portugal squad was never competent enough to win that tournament anyways. 2012 was Probably the best tournament Ronaldo has ever played for Portugal, but then again those were the Spanish times in all international football. So, from like 2008 to like 2016, Portugal was never competent enough to win anything big, but they pulled off that 2016 after Spain's time was over by a miracle and Ronaldo contributed 66% of the goals for Portugal, so i wouldn't necessarily call that a bad tournament for a 31yr old player. Now in 2019, i think Portugal has the very good shot at EURO 2020, i wouldn't even call them underdogs anymore since they got all that talent playing all over the big clubs, having GOAT in their team with B. Silva, Joao Felix, Ruben Neves, Carvalho etc and in Defense, they have Ruben Dias etc coming up so they're pretty much a contender, if not one of the favourites.
Messi and Argentina is whole different story. they're 2 time World cup winners, they have what like 15 Copas on their belt. They have whole different tradition, they have way more "recent" success than Portugal did before Ronaldo and therefore, it would be logical to actually expect them being on the run for the gold. On top of that, they have had way better squads past these years except now, i'd rather have Portugal squad than current argentine squad and that's first time in 15 years. Messi's international career hasn't been nothing but a big dissapointment, i don't even need to go there.
Talking about Mbappe surpassing both of their international careers is just pure idiotism. He happened to be part of France's Golden generation or can you even say "golden generation" when it comes to these absolute big nations in football, but France already reached 2016 EURO final without Mbappe and then 2018 WC with him and things ain't looking bad for them just by looking the core of that team so it might end up them winning 2020 EURO as well. It's absurd to expect these so called smaller nations to actually pull off a win in the WC or even EUROS and seriously, as a guy from Finland i'd not be happier than seeing my country even qualifying for one EURO or WC in my lifetime so, that's how tough it is for these smaller nations.
About GOAT tiers in my lifetime because im not going to rank something i haven't seen other than Youtube:
Tier 1. Cr7
Tier 2. Zidane, Brazil Ronaldo, Messi, Ronaldinho etc.