Quick benchmark of delete_prefix, sub, and gsub based off https://twitter.com/JemmaIssroff/status/1368204231476469760?s=20

delete-prefix.rb

require 'benchmark/ips'

Benchmark.ips do |bm|
  MAX_LENGTH = 280

  long_string = 'YOLO: the return of the comeback'

  bm.report('delete_prefix') do
    long_string.delete_prefix('YOLO: ')
  end

  bm.report('delete_prefix!') do
    long_string.delete_prefix!('YOLO: ')
  end

  bm.report('sub') do
    long_string.sub('YOLO: ', '')
  end

  bm.report('sub!') do
    long_string.sub!('YOLO: ', '')
  end

  bm.report('gsub') do
    long_string.gsub('YOLO: ', '')
  end

  bm.report('gsub!') do
    long_string.gsub!('YOLO: ', '')
  end

  bm.compare!
end

results.sh

Warming up --------------------------------------
       delete_prefix   503.777k i/100ms
      delete_prefix!   938.312k i/100ms
                 sub   364.851k i/100ms
                sub!   446.770k i/100ms
                gsub   408.128k i/100ms
               gsub!   460.125k i/100ms
Calculating -------------------------------------
       delete_prefix      7.569M (± 3.4%) i/s -     38.287M in   5.064362s
      delete_prefix!      9.272M (± 2.1%) i/s -     46.916M in   5.062187s
                 sub      3.767M (± 4.6%) i/s -     18.972M in   5.048189s
                sub!      4.716M (± 1.6%) i/s -     23.679M in   5.021810s
                gsub      4.124M (± 2.5%) i/s -     20.815M in   5.050811s
               gsub!      4.708M (± 4.9%) i/s -     23.926M in   5.097267s

Comparison:
      delete_prefix!:  9272140.6 i/s
       delete_prefix:  7569230.2 i/s - 1.22x  (± 0.00) slower
                sub!:  4716448.4 i/s - 1.97x  (± 0.00) slower
               gsub!:  4708396.1 i/s - 1.97x  (± 0.00) slower
                gsub:  4123799.2 i/s - 2.25x  (± 0.00) slower
                 sub:  3766876.1 i/s - 2.46x  (± 0.00) slower