Yan haklar iyileşmedikçe iş güvencesi tek başına yetmez.

Yan haklar means employee benefits, fringe benefits, or perks.

• yan = side
• hak = right
• haklar = rights

So the literal meaning is something like side rights, but in normal Turkish this refers to extra benefits connected to a job, such as insurance, meal support, transportation, bonuses, and similar advantages.

It is plural because people usually talk about a package of benefits, not just one.

İyileşmedikçe comes from:

• iyileşmek = to improve, to get better
• -me- = negative suffix
• -dikçe / -dıkça / -dukça / -dükçe = a suffix that creates an adverbial clause

So:

• iyileş- = improve
• iyileşme- = not improve
• iyileşmedikçe = unless it improves / as long as it does not improve / until it improves

In this sentence, it refers to yan haklar, so the sense is:

unless the benefits improve
or
as long as the benefits do not improve

That is a very common feature of this Turkish pattern.

With a negative verb, -medikçe often expresses a condition that continues to block something. So it can be translated in English in a few ways depending on context:

• unless ...
• until ...
• as long as ... not

Here, the idea is:

Job security alone is not enough as long as benefits do not improve.

That is why unless the benefits improve is also a natural translation.

So the Turkish form is a bit broader than a single fixed English word.

Because iyileşmedikçe is not a fully conjugated finite verb here. It is a subordinate, adverbial verb form.

In Turkish, forms like -dikçe usually do not show person/number agreement the way a main verb does. The subject is understood from context.

So in this sentence:

• yan haklar = the subject of the subordinate idea
• iyileşmedikçe = unless they improve / as long as they don't improve

English needs they, but Turkish does not need to mark that explicitly here.

İş güvencesi means job security.

It is a noun compound:

• iş = work / job
• güvence = assurance / security / guarantee
• güvencesi = the compound form with the third-person possessive-type ending

This is a very common Turkish structure. In noun compounds, the second noun often takes this ending:

• iş güvencesi = job security
• ev kapısı = house door
• okul müdürü = school principal

So the -si here does not mean his/her in the ordinary sense. It is part of the normal compound structure.

Because these two expressions mean different things.

• iş güvencesi = job security
  the security of keeping your job, protection against dismissal, stable employment

• iş güvenliği = workplace safety / occupational safety
  safety at work, protection from accidents and hazards

So in this sentence, iş güvencesi is the correct phrase because the topic is employment conditions, not physical safety.

Tek başına means alone, by itself, or on its own.

So:

• iş güvencesi tek başına yetmez
  = job security alone is not enough

The phrase emphasizes that job security, by itself, is insufficient. Something else is also needed — in this case, better benefits.

Yetmez comes from yetmek, which means to be enough, to suffice.

• yeter = it is enough / it suffices
• yetmez = it is not enough / it does not suffice

This is the aorist form, which is often used in Turkish for:

• general truths
• general statements
• what is typically or characteristically the case

So here yetmez does not just describe one moment. It states a general idea:

Job security alone is not enough.

The sentence is:

Yan haklar iyileşmedikçe iş güvencesi tek başına yetmez.

A natural breakdown is:

• Yan haklar iyileşmedikçe = unless benefits improve
• iş güvencesi tek başına yetmez = job security alone is not enough

Turkish often puts the condition first and the main statement after it. That is very normal.

Also, the main verb usually comes at the end, so yetmez appears last.

You could rearrange some parts for emphasis, for example:

• İş güvencesi, yan haklar iyileşmedikçe, tek başına yetmez.
• Tek başına iş güvencesi, yan haklar iyileşmedikçe yetmez.

But the original version is natural and clear.

Yes. Turkish often leaves things implicit when they are clear from context.

For example:

• English might say unless the benefits improve
• Turkish just says yan haklar iyileşmedikçe

There is no separate word for they. The subject is understood from yan haklar.

Also, there is no word like it in yetmez. English says it is not enough, but Turkish simply uses the verb yetmez.

So Turkish is often more compact than English in sentences like this.