Exchange-traded funds (ETFs) can make it much easier to invest in markets and industries that are difficult to access through individual ASX shares.

There are several Betashares funds I like, but these three stand out to me as long-term investments I would be happy to own.

Betashares Global Cybersecurity ETF (ASX: HACK)

Cybersecurity is becoming increasingly important as businesses move more of their operations online.

Companies now store enormous amounts of sensitive information digitally, while cloud computing, remote work, artificial intelligence, and connected devices are creating more potential points of attack.

That means cybersecurity spending is becoming harder for businesses and governments to avoid.

The HACK ETF provides exposure to a collection of global stocks involved in areas such as network security, cloud protection, identity management, and threat detection.

I think it makes sense to use an ETF for this industry because technology changes quickly. Today's strongest cybersecurity company may not necessarily remain the leader a decade from now. The HACK ETF allows investors to back the broader growth in cybersecurity spending without relying on one company to get everything right.

Betashares Global Healthcare ETF (ASX: DRUG)

Healthcare is another area I would be comfortable investing in for decades.

The DRUG ETF provides exposure to major global healthcare businesses across pharmaceuticals, biotechnology, medical devices, and other parts of the sector.

I think there are several reasons demand could keep growing. Populations are ageing in many developed countries, new treatments continue being developed, and medical technology is improving what doctors can diagnose and treat.

For me, this ETF offers a simple way to gain exposure to healthcare innovation without needing to predict which individual drug or medical technology becomes the biggest success.

Betashares Global Shares ETF (ASX: BGBL)

My final choice would be much broader than the others.

The BGBL ETF provides exposure to a large collection of companies across developed markets outside Australia.

I like it because an investor can gain access to many of the world's leading businesses through one relatively simple holding.

It also fills some gaps that naturally exist in the Australian share market. Global markets offer much greater exposure to industries such as technology, healthcare, consumer brands, and industrial businesses.

For someone building wealth over many years, I think having part of a portfolio invested beyond Australia makes a lot of sense. The BGBL ETF could therefore serve as a long-term core holding.

Foolish takeaway

I would be comfortable owning all three of these Betashares ETFs for the long term.

What I like most is that they give me access to opportunities that are difficult to capture through the ASX alone, while still keeping the investment process straightforward.

For investors prepared to stay patient, I think the HACK, DRUG, and BGBL ETFs are three funds worth considering.