3D printing filament is one of those subjects where people can turn a fairly simple decision into a religious argument.

PLA is not bad. PETG is not automatically better. ABS is not obsolete.

They are materials with different properties.

Pick the material based on the job.

PLA

PLA is usually the easiest place to start.

It prints easily, produces good surface quality and is widely available.

It is excellent for prototypes, decorative parts, brackets, organizers and many indoor functional objects.

The downside is heat resistance.

Leave a PLA part in a hot car and you may eventually discover that your carefully printed bracket has become modern art.

PLA can also be more brittle than PETG in situations where impact resistance matters.

PETG

PETG sits in a useful middle ground.

It is generally tougher and more impact resistant than PLA and handles heat somewhat better.

It is a good choice for functional parts, mounts, containers and components that need more abuse than a decorative PLA print.

The tradeoff is that PETG can be more annoying to print cleanly.

Stringing is common. Bridging can be different. Surface finish can vary. Bed adhesion can become extremely enthusiastic.

PETG is good.

PETG is not magic.

ABS

ABS has a long history in functional manufacturing and remains useful when heat resistance, toughness and durability matter.

The problem is printing it.

ABS tends to shrink more during cooling, which can cause warping and layer adhesion problems.

An enclosed printer helps.

Ventilation also matters because printing ABS can produce unpleasant and potentially harmful fumes and particulates.

This is not the material I would choose simply because somebody told me it is "professional."

If PLA does the job, use PLA.

Heat Matters

The most common mistake is choosing filament based on strength while ignoring temperature.

A part can be mechanically strong and still fail because it softens.

Think about where the part will live.

Inside an air-conditioned room? PLA is probably fine.

Near a hot motor? Maybe not.

Inside a vehicle parked in the sun? Think carefully.

Near a heated enclosure or industrial environment? Now material selection matters a lot more.

Mechanical Strength Is Not One Number

When somebody asks "Which filament is strongest?" the answer should be:

Strong in what way?

Tensile strength? Impact resistance? Layer adhesion? Flexibility? Heat resistance? Fatigue? Creep?

The print itself also matters.

Layer orientation can dramatically affect the part.

A mechanically strong material printed in the wrong orientation can still fail along layer lines.

Drying Matters

Some filaments absorb moisture.

Wet filament can produce poor surface quality, popping sounds, inconsistent extrusion and weaker prints.

PETG is particularly worth paying attention to.

Do not immediately blame the printer when the real problem is a spool that has been sitting open in humid air.

Material storage is part of printing.

My Simple Rule

Use PLA when it is good enough.

Use PETG when you need more toughness, flexibility or environmental resistance.

Use ABS when you specifically need its properties and have a printer setup that can handle it properly.

Do not choose a material because it sounds more advanced.

Choose it because the part requires it.

What Actually Matters

The best filament is not the strongest filament.

It is the material whose properties match the application.

A perfectly printed PLA bracket that survives five years is better than an incorrectly printed ABS bracket that fails in three weeks.

Engineering beats marketing.

Even in a hobby printer.