The only passage that I know of that Christians interpret to be a commandment to contribute into a church treasury is 1 Cor 16:1-3. If this passage doesn't mean what we have traditionally ascribed to it, then I know of no scriptural requirement to give into a church treasury each week. Assuming that the traditional interpretation of the above passage is lacking sufficient grounds to bind it, why would Christians decide to take up a collection at all? I think the answer is that we don't have to and if we do, it is a judgment call based upon expediency.
For example, if we decide to have a building to facilitate our meetings, then costs will be involved. One expedient way to cover those costs is to take up a collection. The people who give do so with the understanding that they are paying for the building and/or its associated expenses. On the other hand we might decide to meet in homes. If we do this, the costs associated with meeting would be virtually eliminated and a collection may not be needed at all. Either way is a judgment call. Another example could be that a local group of Christians decided that they all wanted to support a preacher somewhere. Each person could send the money directly to the preacher. Perhaps a more expedient way would be to take up a collection during an assembly and have one person send the money. Either way is a judgment call. It is given with the understanding that it will be spent for such purposes as the group has approved. If it is spent in a way which the group has not authorized, then it has been misappropriated which brings along a number of ethical, moral and legal problems.
Some would argue that the church has work to do that is somehow separate and apart from the work given by individual Christians and therefore it needs money to carry out such works. If we really think this, then I would argue that we have an unscriptural idea of what the church actually is. This thinking is akin to the idea that the church is some sort of corporate entity instead of being composed of simply a group of Christians. Since the church is a group of Christians, then it is up to individual Christians to work. If the individuals are working, then the church is working and that is the only way the church can work. For example, it is said that based upon 1 Tim 5:16 that the church has a work to do that requires money. I agree with this if by the word "church" you mean a group of individual Christians. However, this doesn't mean that a collection must be taken up in order to support widows. Individually, Christians could assist the widows financially and in other ways. As a matter of fact, not all of their needs can be met by money! I agree that it is probably more expedient to take up a collection, but it doesn't have to be done by means of a group collection. There are other options and as in the examples above, it is a judgment call.
There is no command in the New Testament to take a weekly collection nor are collections required in order to carry out the work of the church. What work has God given the church that can not be accomplished without a collection? As is noted above, there are other options and the decision to take up a collection is a matter of judgment amongst a local congregation.