Use works as both a verb and a noun, and the pronunciations differ.
I use my old bike, so it sees a lot of use. The first use is the verb /juːz/, employing the bike. The second is the noun /juːs/, the act of using.
One sentence, two jobs
Use plays two parts, and the sound changes with the job. As a verb it ends voiced, /juːz/ with a z sound. As a noun it ends voiceless, /juːs/ with an s sound.
One sentence shows both roles at once. I use my old bike to get to work, so the bike sees a lot of use contains the same spelling twice, but the word changes shape between the two clauses.
Start with the first job. In I use my old bike, the word is a verb meaning to employ something, so it tells us what the speaker does with the bike, and the verb takes the voiced ending /juːz/.
The second clause hands the word a different role. In the bike sees a lot of use, it works as a noun, the act of being utilized, so the ending goes voiceless, /juːs/.
The cause is the grammatical role, so the result is the sound shift. Employing the bike produces a noun for that employing, and the final consonant changes because the word's job changes.
A rough analogy is record, because the verb for recording a song stresses the second syllable while the recording itself stresses the first. The meaning stays related, but grammar flips the form, and here that flip sits at the final consonant.
Where this explanation stops
This /juːz/ versus /juːs/ contrast covers only the bare verb and the noun forms. It does not extend to other patterns built on the same word.
The same caution applies to phrasal verbs like use up and to fixed expressions like in use, where the pronunciation pattern here may not be a reliable guide.