Typically, the publication of the amount of funds collected by developers says that the project should be trusted. Many investors pay much attention to this.
You're right. Only if you can buy project tokens using different coins, then the fees will be held on a large number of wallets. And it is not always possible to publish them all.
Recently, for many developers, it is popular to allow users to invest through a personal account and give everyone their wallet address for investing. Thus, it is very difficult to track how much money is collected.
If fees go through a personal wallet for each investor, then it is very difficult to track the total amount of project fees. Do not hesitate to show the amount of money collected.
It is best to see the progress of fees at single wallets intended for investment. In this case, each investor can check how much money was raised during the investment.