Why isnt accounting net income used in the net present value and internal rate of return methods

Question:

Why isn’t accounting net income used in the and methods of making decisions?

Net Present Value
What is NPV? The net present value is an important tool for capital budgeting decision to assess that an investment in a project is worthwhile or not? The net present value of a project is calculated before taking up the investment decision at... Internal Rate of Return
Internal Rate of Return of IRR is a capital budgeting tool that is used to assess the viability of an investment opportunity. IRR is the true rate of return that a project is capable of generating. It is a metric that tells you about the investment... Capital Budgeting
Capital budgeting is a practice or method of analyzing investment decisions in capital expenditure, which is incurred at a point of time but benefits are yielded in future usually after one year or more, and incurred to obtain or improve the...