Travel media skews toward expensive destinations and luxury options. Plenty of comfortable, enjoyable travel costs £80-120/day for adults with the right destination choices. The expensive travel is the loud part; affordable travel is more available than the marketing suggests.
Where £80-120/day is comfortable adult travel
Portugal (outside Lisbon centre). Slovenia. Czech Republic outside Prague centre. Hungary. Romania. Most of southern Spain outside major tourist zones. Vietnam, Thailand, Cambodia at £40-60/day. Turkey outside Istanbul centre.
Where it's structurally impossible
London, Paris, Amsterdam. Switzerland, Norway, Iceland in peak season. Tokyo and most of Japan. New York. £180-250/day minimum for genuine adult comfort.
Pick destinations matched to budget rather than fitting destinations into wrong budget. Comfortable budget travel exists in abundance for those who choose accordingly.