。
Leisure is regarded as a means to an end.
Literal
Free-time [topic-は] purpose for-の means [quotative-と] consider-[passive-られる]-[ongoing-state-ている].
A written, abstract statement. Note the chain 目的のための手段 — literally 'a means for the sake of a purpose' — where the nested の structure shows how Japanese builds noun phrases through repeated linking. The verb cluster 考えられている layers three pieces: 考える + passive ~られる + resultant-state ~ている, yielding 'is [currently] thought of as.' This is a characteristic shape for impersonal written claims.