A pip is the smallest standard unit of price movement. Expressing P/L in price distance rather than money makes it easier to compare EAs on different pairs or account sizes.
A pip is the standard smallest unit of exchange-rate movement. Expressing results in "distance" rather than "money" lets you compare trades regardless of lot size or capital.
"Total pips gained" gauges strategy skill independent of capital or lot size. But since the money value per pip changes with lot size, judge final profitability with money-based expectancy and PF.
