My experience is quite the opposite. I didn't have nearly the growth until God took me to a house Church.
One thing critics of house churches on this page seem to miss is that all churches are independent groups that need to be vetted, and we always need to be looking for God's lead whether it's to a house Church or other.
As for the complaint that they aren't accountable to anyone, are not all churches accountable to God? If you're accountability is to anyone else you have a problem no matter the location or size of your gathering.
And no, you don't need a designated leader. Holy spirit is perfectly capable of leading, though it can take time for people to unlearn old, unbiblical patterns of a priest/entertainment model that ignores the universality of the Holy Spirit's availability and the need for all parts of the body to be utilized to edify the church (1 Corinthians 12). Frank Viola has written extensively on the history of how we got here in the book
Pagan Christianity that is well worth a read, as well as several books on house church, though I have not read the latter myself. I did listen to an interview with him about one of them on the Cold Case Christianity podcast, though, which can be found
here (Link will open Spotify app).
You do need spiritual elders, however, to keep things on track. Biblically speaking an elder is just a mature Christian. You also need a biblical shepherd to guard against the wolves, but this is very different from our modern idea of 'pastor.' In my house church at God's directive Jesus is our shepherd, though I would not assume that for every group. I can't say I fully understand the role since Jesus certainly does more than that for our fellowship, but it is something to seek God on rather than defaulting to common definition.
Oh, also of note, God indicated to our fellowship that when starting a house church, it is improper to start it in your own home since this tends to make us think it is our church instead of God's.
As for the concern of someone previewing how they might rob someone's house, that only makes sense if you are assuming it's a drop in church like big churches usually are. House churches tend to be much more personal places where you either know everybody who's coming already, or someone you know well is the person inviting them. Furthermore, why are we leaving God out of the equation? We should not be foolish but faith in God means trusting Him enough not to live in fear, especially when it comes to furthering his Kingdom.