I had to give Uiua another go today. (run it here)
{"Card 1: 41 48 83 86 17 | 83 86 6 31 17 9 48 53"
"Card 2: 13 32 20 16 61 | 61 30 68 82 17 32 24 19"
"Card 3: 1 21 53 59 44 | 69 82 63 72 16 21 14 1"
"Card 4: 41 92 73 84 69 | 59 84 76 51 58 5 54 83"
"Card 5: 87 83 26 28 32 | 88 30 70 12 93 22 82 36"
"Card 6: 31 18 13 56 72 | 74 77 10 23 35 67 36 11"}
LtoDec ← ∧(+ ×10:) :0
StoDec ← LtoDec▽≥0. ▽≤9. -@0
# Split on spaces, drop dross, parse ints
≡(⊜□≠0.⊐∵(StoDec)↘ 2⊜(□)≠@\s.⊔)
# Find matches
≡(/+/+⊠(⌕)⊃(⊔⊢↙ 1)(⊔⊢↙¯1))
# part 1
/+ⁿ:2-1 ▽±..
# part 2 - start with matches and initial counts
=..:
# len times: get 1st of each, rotate both, add new counts
⍥(⬚0+↯: ⊙⊙∩(↻1) ⊙:∩(⊢.))⧻.
/+⊙;