Actually the limited substitutions makes soccer a bit more challenging, tactically. I’d hate to see that aspect go, because it would make things too easy to adjust - if you think it’s low-scoring now, imagine being able to sub in an “all out defense” lineup as soon as you go up 1-0.
I do think however in Extra Time, they should waive restrictions on substitutions and play on until somebody scores.
I really don’t understand why they don’t go with The Golden Goal.