If it's a condo, it almost has to have an HOA. And if there is an HOA (or COA, I'm using them interchangeably here), there is an HOA fee. How else would they pay for insurance, landscaping, and shared amenities such as the roof and parking lot?
There are several very good reasons many investors steer clear of condos:
1. As noted above, the HOA is responsible for the shared amenities (roof repair/replacement, parking lots, pools, pest control, landscaping, etc). So you give up control over how, when, and for how much these things are done.
2. The HOA has to pay for these things, and they do so by collecting monthly or quarterly HOA fees in most cases, which cuts into your cash flow as an investor, or your buying power as an owner occupant.
3. When major repairs are beyond the operating budget of the HOA, they can assess the owners a one time fee for things like roof replacement, recladding the buildings, or refinishing the pool. So in addition to your $600/mo (or whatever amount they are) HOA fees, you might also get hit with a one time assessment of $20,000 (or whatever amount the HOA deems necessary) for repairs or capex.
So you really have to dig into the financials of the HOA and any looming assessments during due diligence.
4. The HOA often controls things like whether or not you can rent your unit to a tenant. Some HOA's don't allow it at all, some want to screen, meet, and interview your tenants themselves before approving, which can cause delays and/or scare off potential tenants. At the other end of the spectrum, some HOAs may be completely hands off and let the place go, to the point no one wants to live there.
5. Some HOAs even control whether or not you can sell your unit and who you can sell it to. I've seen HOAs who require a potential buyer to sit down in an interview with the HOA to determine whether they are a "good fit".
6. HOAs are responsible for "policing" the grounds. They often control what colors you can paint your exterior and doors, what color and condition your window screens must be kept in, where you can park, and what condition your vehicle must be kept in (I've literally had an HOA tell a resident they could not park their car on the property because it was too ugly).
7. Things like the HOA financials, the percentage of owner occupants, and the percentage of units owned by the same person or entity (which are largely out of your control) determine whether the units in the complex are "warrantable" and can be financed using conventional Fannie/Freddie financing. This makes many condos a cash (or private financing) only asset. And this can change over time, potentially leaving you stuck with a much less desirable asset at some point in the future if the development becomes non-warrantable.