Agree CL needs a big reform and the qualifying process for some leagues/teams is tough.
But the reason those teams you mentioned get in without qualifying rounds is because of coefficient. It?s done over a 5 year period so if your league/teams consistently do well in European competition it can become easier to qualify.
For example Serie A got a 4th Champions League spot instead of 3 from 2018/19 because of their coefficient. Italian teams must have been doing well over that 5 year period to get it. Scotland gained another spot last season
https://www.bbc.co.uk/sport/football/53688401 etc etc
So those teams you mentioned from leagues outside of the usual top 5 would need to perform well in Europe to make it easier for them to qualify. It?s not handed out on a plate. The current system even though it?s not perfect is still fairer than what Super League was suggesting. That would have seen those other leagues fall into irrelevance.
Since I am from Croatia, for example, Dinamo Zagreb reached quarters of Uefa league this season, winning 3:0 against Tottenham.
In 2019 in Europa league they won the 1st place with 4 wins and 2 draws.
This season in a group stage again 4 wins and 2 draws against Dutch Feyenoord, Cska Moscow and an Austrian club, all 3 clubs from countries who have better national coefficients.
Later they KO'd another Russian club with better coefficients and then they KOd Mourinho's Tottenham from the richest league in the world, only to lose to Villareal in the end (with all 4 penalty calls in Villareal's favor, of course).
Last year they trashed Atalanta 4:0 in a CL for example.
So, they have some really decent European results.
But since our country is poor, all teams except Zagreb are really poor and bad.
Zagreb won 15 out od the last 16 league titles.
And then, national coefficients are calculated based on all clubs from your country.
And other clubs are European minows like Rijeka, Hajduk and Lokomotiva.
Look at their results this season.
Uefa, qualifiers:
Hajduk:Macedonian team 1:0
Hajduk:Galatasaray (lol) 0:2, goodbye
Osijek:Basel 1:2, goodbye
Rijeka:Ukranian team 2:0
In Uefa league group stage, Rijeka had 1 win, 1 draw and 4 defeats.
CL qualifiers: Lokomotiva:Rapid Wien 0:1
Uefa qualifiers: Lokomotiva:Malmo 0:5, goodbye
So, Dinamo alone played 15 matches in Europe this season, with 9 wins, 2 draws, 4 defeats.
All other Croatian teams combined had:
12 matches:
3 wins, 1 draw, 8 defeats.
So, Dinamo Zagreb alone = 9 wins
4 other Croatian clubs = 3 wins.
And since country's coefficients are divided by a number of teams who played in Europe that season, Dinamo's wins are divided with 5.
So, even if they won 29 points for themselves, our Country won only 5.8 points from Dinamo, 1.4 points from Rijeka, 0.6 points from Hajduk, 0 from Osijek, 0 from Lokomotiva.
So, you see, countries are depending on other teams from their country.
And if football is poor, if there is no money from sponsors (or from a CL/Uefa league) HOW to improve a quality of other teams in your country, and they will always pull you down in coefficients.
Next season Dinamo will again have to play 3 random KO qualifying matches to reach CL or even Uefa league group stage.
And this season, those KO matches were even one-legged due to COVID.
Imagine playing 3 random one legged KO matches (on neutral ground or 1 away match) against Champions from other countries.
Barca is struggling on any KO away match, yet these teams often play only 1 KO match on an away ground.
So, champions from Sweden, Norway, Poland, Romania, Bulgaria, Croatia, Serbia etc have to go through 3-4 qualifying rounds and play against eachother for 2-3 spots in the end, while Atalanta or Tottenham get a direct CL group stage spot.
And even then Dinamo wins 4:0 vs Atalanta or 3:0 vs Tottenham.
And what is their prize for the next season?
1) dear Zagreb, you will play rounds 2, 3 and 4 in qualifiers
2) dear Atalanta/Monchengladbach = your secured group stage spot is waiting for you, welcome, nice to see you again.
You do have theoretical chances to reach a CL or KO rounds in Europe.
But chances, maths, too many qualifiers matches are totally against countries outside of top10.
CL is open for:
Top 5 countries: England, Spain, Italy, Germany, France
Somewhat opened for:
Portugal, Netherlands, Russia, Turkey, Greece
And more or less closed for other 45 European countries (there are 55 countries in total).