What you dont mention is that the CL had less good teams since there was only 1 for each country.
The UEFA Cup had 2, 3 and sometimes 4 teams from each country so was arguably harder to win than the CL, plus there was an extra round to get through.
The CL now has all the best teams in it now, so obviously it is much harder to win so a comparison is pretty daft.
CL had 2 teams from a winners from the previous season and a champion from other countries.
In today's world, it would be:
1. let's say Barca wins it
2. Real Madrid gets the 2nd Spanish spot
3. Man City
4. Bayern
5. Juve
6. Psg
7. Porto
8. Ajax
Whom are you losing in today's world?
1. Atletico Madrid
2. nobody from France, Italy or Germany because everyone outside of Bayern, Juve and Psg are horrible (Roma, Inter, Milan, Borussia, any French team)
3. you lose Liverpool, Chelsea, Tottenham
Also, back then there was no group stage, but KO rounds from the round of 32.
And KO rounds create more upsets than group stage since Barca/Real and big teams were KOd in the group stage for the last time somewhere in 2001'.
Also, before Bosman rule, you could had only 3 Non EU players in your team.
EU was only a Western Europe with 12-14 countries (iirc) back then.
South America, Eastern Europe, Africa, Asia, Australia, Usa were all foreigners.
Also, a lot of Eastern European countries didn't allow their players to leave their country, so champions of former Soviet Union (currently Russia, Ukraine and 10s of other countries), Romania, former Yugoslavia (currently Croatia, Serbia, Slovenia, Bosnia etc), former Czechoslovakia (currently Czech Republic and Slovakia), Poland, Bulgaria etc were basically NT teams.
So, we didn't have Chelsea and Liverpool, but Milan and Barca had to play with only 3 foreigners against NT teams of crazy Eastern Europeans. That's basically like playing an NT team of Croatia, Russia, Ukraine, Poland, Czech today in 2 KO matches where everything is possible, without VAR and in the days when refs allowed butchering tackles on the opponents.
Think about this to see whether a CL (Champions cup was easy back then):
Real and Barca from 1966 to 1992 in 25 years won 0 CL trophies.
And played only 1 final each (and lost both: 1981 Real, 1986 Barca).
Or until 1998 when Real started to dominate the world again, Real and Barca played 15 and 6 CLs since 1966.
Real won 0 titles in 15 attempts.
Barca won 1 in 6 (1992 title).
So, to some extent, we might say that Real started to dominate after the Bosman rule and when Eastern European countries started to sell their players to Italy, Spain and England.
When rich got richer, Real and big clubs started to buy tens of South American with false passports and players like Modric, Rakitic, Kovacic, Mandzukic, Oblak and co who would have played only for domestic Eastern European teams in the past.
As for the ballon d'or, only European players were eligible for that so players like Zico, Romario and Maradona couldnt win it, so again easier to win.
Van Basten was great though, but nowhere near Messi's level.
About Ballon D Or, Van Basten won it in 1988, 1989 and 1992:
1988:
Van basten won Seria A with Milan infront of Maradona who finished 2nd.
And Netherlands won Euro 88 with him scoring in a final and being MVP of the tournament.
Romario just came to Europe, to Psv.
= so, a deserved win for Van Basten even in today's terms
1989:
Inter won Serie A infront of Napoli and Milan.
Milan won a CL with a 4:0 win over Steaua.
Brasil won Copa America with 6 goals from Bebeto and 3 from Romario.
So:
Van Basten won a CL with 10 goals in 9 matches. Plus 33 goals in 47 matches for Milan.
Maradona won nothing.
Romario won Copa America, but Bebeto was the best scorer.
= when you sum it all, CL wins again since Bebeto was Brasil's best player but he played at Vasco in Brasil, far from the eyes of journos.
= so, a win for Van Basten again in today's terms, right?
1992:
Milan won Seria A. Van Basten scored 25 goals in 31 Seria A matches, he was again an MVP on Euro 1992
Maradona was serving a 15 Month ban from football due to failing a cocaine test.
Romario was injured and scored only 9 goals for Psv.
= so, it was Van Basten vs Barca's Stoichkov that season. But since Bulgaria hasn't even qualified for Euros, you know that journos vote for players based on World cup/Euros and CL wins combined.
So, about his 3 Ballon D Ors, Romario and Maradona didn't interfer too much back then.
The problem was especially zero CL titles for Maradona and Romario in their career.
Even today, who was the last BDOr winner without CL titles previously in their careers?
Cannavaro in 2006, Ronaldinho in 2005 and Nedved in 2003.