No, ultimately it is less accurate.

Liquid depth can be determined from pressure measurements and the reason can be seen by looking at the fundamental (and simplified) equation for calculating the pressure at a particular depth in a liquid; it is:

p = dgh

where:

p is the pressure.
d is the density of the liquid.
g is the local value of gravitational acceleration.
h is the vertical distance (height) of the liquid surface above the level at which the pressure value is being determined.

and so by rearranging the equation the distance of a sensor below the surface of a liquid is given by:

h = p/dg

So, if the values of pressure, liquid density and gravitational acceleration are known the depth can be calculated and indeed most depth gauges are pressure gauges scaled to read directly in ‘h’ and not ‘p’.

For such depth gauges to work, however, assumptions have to be made about the value of the other parameters – especially the liquid’s density.  This will vary with composition, purity, time, temperature and at different locations in the reservoir etc; indeed these parameters will not be known very accurately at all and it would be major task to measure and monitor them. But a gauge that is scaled, for example, in metres of water hides these problems and, where accuracy is important, can lead to a false sense of security. If the pressure gauge is sent for calibration the calibration provider will not be sure what a metre of water is in your particular application and indeed you will not be able to specify it accurately either; it cannot be well defined let alone realised. The same problem exists with inches of water, feet of oil etc; these units can only be used by making very significant accuracy-limiting assumptions about the liquid in question.

If accuracy is not very important, it is of course much easier and convenient to read a depth gauge scaled in units of length rather than pressure and there is no reason why this should not be done in many applications where the reading might be considered - in the quasi-legal sense - to be 'for indication only'.

But if accuracy is important the procedure for using a pressure gauge to estimate liquid depth should start with use of a gauge that has been calibrated in pressure units (preferably pascals - or multiples/submultiples thereof such as kilopascals, megapascals etc). The pressure values indicated should then be converted to length (depth) by using locally evaluated information and estimates about the density of the fluid and the value of gravitational acceleration. Clearly this takes very much more effort than simply reading a gauge that is somewhat arbitrarily scaled in metres of water but the effort is necessary if it is important to know the accuracy of the depth measurements being made.