Let's not forget that Toronto make some deadline deals that won them a title.
The amount of times I've heard that this year, you'd think Toronto has now authored the book on the only way to win a championship.
Just because Toronto did something, and won a championship, doesn't mean that's the exact blueprint that needs to be followed every year to win. And saying that tends to ignores the other 20 moves they made in the 2-3 years leading up to their '19 championship to get there (trade for Kawhi, re-sign Lowry/Ibaka, draft Siakam at 27, get production from nobodies like VanVleet and Powell, etc.). It wasn't just trading for Gasol that won them the championship, it was the culmination of all their moves.
Many teams have won a championship without making a trade (of significance). Even excluding heavy favorites (like GS): 2014 Spurs only traded for a guy who played 6 mins in the playoffs despite 4th best record at the deadline. 2011 Mavs didn't make a trade despite having only the 4th best record at the deadline. 2007 Spurs didn't make a trade despite being 3rd in the West. I want to give more examples, but really most of the time the heavy favorite wins (GS, MIA, LAL, BOS, etc.), even despite other teams making moves.
Just because the '19 Raptors or the '04 Pistons (Sheed) won a championship by trading for a key starter at the deadline, doesn't mean that any team that wants to win a championship needs to do that too. There are many different paths to a championship.