Talk about cherrypicking. Belgium currently has a strong national team, which they didn't for a very long time. Sweden has more international medals than Belgium overall. Portugal can play football all year around and is primarily a football nation only. Still, Portugal has basically only been successful during this late era.
Speaking of handball, funny how we should just ignore Sweden was the powerhouse in handball for a very long time (a decade or so, 1990s to 2000s). Also the only nation that once challenged China in table tennis, having produced some legends in that sport. Not to mention the former legends in tennis, track and field, skiing, etc. Also having the best player in carambole history (Torbjörn Blomdahl), considered the most difficult form of snooker/ billiard).
You're talking bollocks, Sweden has punched way above their weight in many sports. That the country has a dip sports wise now is because of many reasons. One big reason is so many young Swedish athletes choose to play that ridiculous sport floorball, e-sports and the alarming reports that incredibly many children between 7-12 don't participate in sports, or quit. The decline in sports activities is as much as 37% and 233 of 290 municipalities have seen a decline.