1st team in history to win 7 games (actually 6 was already the record)
Team with more goals in an Euro edition (15)
Spain won against 4 World Champions (Italy, Germany, France, England). I doubt this has ever happened before in a major tournament.
"Underdog", maybe not in the strict meaning of the word but it wasn't the favorite. It had to win to all the favorites (Germany, France, England).
And all with positive football, trying to go forward. A group of players that always believed. They had to face many and different tricky scenarios (goals in psycological minutes, injuries...) and they always thrived on them. The NT was very critizised before the Euro (RFEF scandals, coach and team election...) not even winning the Nations League helped, but here we are. They won the Spanish fans (and I think many outside) during the tournament. First title I enjoy not been one of the clear favorites. Fantastic.
From the BBC, France had more shots, more shots on target, way more touches in the opposition box, etc, which you can find here:
https://www.bbc.co.uk/sport/football/live/cd1derpyngmt#MatchStats
And France had a higher xG, which you can see here:
Man, you (not just you, just in general) should watch more football and read less "stats", that can say a very different story from reality. Football is complex.
XG is just another ultrabiased stat that should be taken as a grain of salt. It can be useful to understand how clinical you are in a season, but it shouldn't be taken as the "holy grail" of what a team deserves or not. It is inherently biased in how it is calculated (i could talk hours about this) but more important, it doesn't take into account context.
For example, that France game. Spain had a great change in the first minutes (Fabian), just 2 minutes later France scored (min ~8). It took less that 20 minutes to Spain to put 2 goals against the best defense of the tournament. 1 banger (low xG) and another great goal by Olmo. Ok, Spain had to put pressure on France and got it done real quick. Spain wasn't in need to risk a lot anymore and just was more cautious. France generated barely nothing, but played more in Spanish zone. They accumulated xG with barely chances. They only had 1 good chance in 70 minutes needing to score (min 80 something). Spain scored 2 in 20 minutes. If Spain would be in need... then... well, we don't know, but we know what happened when in need.
Germany game was trickier, Spain was in control of the game until we substituted our best players (around min 60), before we had scored, mostly dominated, and Germany should have had Kroos red carded multiple times. From those substitutions Germany (who had to score at home), started creating chances, and it was like that until the end of 90 minutes (they scored in 88). I guess it was a coincidence that after the draw at the end of the 90 minutes, the german dominion stopped in the extra time, that was very leveled. Well... Germany didn't need it so much and Spain tried going forward again. We scored but it is true that it could have gone one way or another. You always need some luck to win a championship like this. Germany accumulated more XG because of the context. They were behind, just that.
The opener game against Croatia... Spain "lost" XG (or was very similar) but won 3-0. Well... it was 2-0 at 30 min, 3-0 at half time. Spain barely tried and Croatia created some changes.... while big down, yet they didn't score, so Spain didn't try, Why would they?
One goal in football changes context and the dynamics of the match, making XG a very poor stat to actually talk about what is truly deserved.