"It was an incredible journey that felt a lot longer than two weeks here in Madrid," the German, who became the first lucky loser to reach the final of a Masters 1000 event, told a news conference after Alcaraz beat him 6-4 3-6 6-3 on Sunday.
"Of course I would have liked to have gone all the way but I am proud of what I accomplished. I hope it's a turning point in my career and pushes me a lot going forward."
Struff's run to the final was part of a remarkable turnaround in fortune for the German, who dropped outside the top 100 last year but is back up to 65th after reaching the quarter-finals of last month's Monte Carlo Masters.
He claimed a 4-6 6-3 6-4 semi-final victory over Russia's Aslan Karatsev (29) on Friday, days after losing to the same opponent in the final round of qualifying.
Despite his defeat in the qualifier, Struff was added to the main draw after a late withdrawal and enjoyed a fine run, ousting world number five Stefanos Tsitsipas (24) in the quarter-finals.
In the final, he was relentless and forced Alcaraz to play his best to come up with the win in three sets in a packed Caja Magica supporting the Spaniard.
"If you told me two weeks ago that I would have reached the final and played the way I did against Carlos Alcaraz, I would sign it right away," Struff said.
"I have played him twice before and I knew I had to be more aggressive than him. He is a tennis player that can be given space. So I tried to bring it on to him but when he broke me he broke me really well and he was too strong in the end."
